Commentaries, Health September 24, 2012

Vitamin A Wars: the Downsides of Donor-driven Aid

by Jonathan Latham

Ted Greiner, Professor of Nutrition, Hanyang University, Korea (Photo Credit: Jon Orlando)

Surely one of the most precious of human dreams is to become rich and famous by doing good for others. And what could do more good than eradicating global malnutrition? Subtle variations on that theme have muddled the field of international nutrition for decades. Donor governments vary, but most want some proportion, and some want the vast majority, of their “donations” to poor countries to come back to them. Sometimes this is achieved by building up a cadre of domestic experts, or by providing products, including foods to the poor countries that will create preferences that will have to be satisfied by imports in the future. Meanwhile, those who feel uncomfortable with this way of doing things, and who ask why the capacity of developing countries cannot be built, and funds be provided to allow them to independently solve their problems, tend to get labeled as radicals.

Growing leafy greens in India
Growing leafy greens in India

The major focus of international nutrition, in its early years as a serious profession, was protein. Companies and entrepreneurs in the rich countries began to show their concern (all the way to the bank) by developing fish protein, single cell protein, and even protein from microorganisms grown on petroleum. But this agenda came to a screeching halt after 1974 when Don McLaren published “The Great Protein Fiasco” in The Lancet (McLaren, 1974). He pointed out that in nearly all cases traditional diets, when adequate in quantity, provided enough protein. From being at the top of the nutrition policy agenda, protein deficiency has since been relegated to a position of minor importance.

First calories, and then micronutrients (certain vitamins and minerals) began to take center stage. Nowadays the nutrient companies are in the saddle, to the delight of those whose ideology labels the private sector as the source of all that is good. This article summarizes the battle over vitamin A. It looks at how a simplistic and unsustainable donor-driven “solution” rose to prominence and has unscientifically fended off the competing approaches preferred by developing countries. And it asks, now that donors have flooded the world with vitamin A capsules (VAC), what are they going to do once they no longer want to continue pumping so much money into this unwelcome approach.

Mobilizing for vitamin A

In the 1970s and 80s, nutrition planners presented decision-makers with three options for dealing with widespread deficiency of a nutrient like vitamin A (thought at that time to mainly be of concern as a cause of blindness in young children): (1) the short-term, stop-gap measure of providing all young children with megadose capsules (200,000 IU) of vitamin A semi-annually, (2) the medium-term but sustainable approach of fortifying some commonly eaten food or condiment with vitamin A, and (3) the long-term solution (enjoyed by the industrialized countries) of improving the diets of the vulnerable groups. A fourth, infection control, and a fifth, breastfeeding promotion, were sometimes added. The second and third, it should be noted, provide the nutrient to everyone and the third and fifth options provide additional important nutrients.

An early study found that after two years of implementation, a broad approach, called the public health approach, comprising basic health care and sanitation as well as assistance in growing high-carotene vegetables and fruits (Solon et al, 1979), failed to show an impact on vitamin A deficiency (though it did reduce worm infestations and improved child growth). This suggested that a more intensive or longer period of program implementation might be needed. Another evaluation (Greiner and Mitra, 1995) of a very intensive three-year program (home gardening plus nutrition education) found that the third year alone doubled the proportion of preschool age children regularly consuming green leafy vegetables. The study was unable to show a biological impact (on an early stage of vitamin A deficiency, night blindness), but neither was higher VAC coverage.

Around 1990, several clinical trials suggested that providing vitamin A to young children (using only VAC or fortification) reduced young child death rates by about 23% on average (Beaton et al 1993). Results were nevertheless highly variable, with two of the trials demonstrating no impact on mortality. The greatest effect (54%), however, was seen in a trial that did not provide large doses, but rather small dose VAC providing the recommended dietary allowance weekly (Rahmathullah et al, 1990)—in other words, rather close to the way we tend to consume vitamin A. (it is present in large amounts in a few foods but not at all in most foods.)

Donor agencies, then as now in the habit of ignoring nutrition because its solution seems to be either too complex (tends to require multi-sectoral involvement and cooperation) or safely ignored (tackle poverty/underdevelopment as a whole and hunger and malnutrition solve themselves), saw an opportunity to do good while the private sector showed off its good side. As Jonsson wrote, in comparing the protein and micronutrient paradigms: “Both these processes assume mono-causality. In both cases they resulted in simple, cost-effective and easy-to-understand intervention programmes. They fit well with the notion that ‘they’ (children in impoverished countries) lack something that ‘we’ (the richer countries) have, and that we can give them in a simple package (Jonsson, 2010).” Thus VAC offered once again the opportunity of solving a public health nutrition problem through a technical fix, taking the “politics” out of aid and development.

One donor’s discoveries

Unlike the North American donor agencies, which have constantly to prove the worth and impact of their work to their doubtful taxpayers, European donor agencies tend to work quietly, knowing they have the support of most of the people whose money they are spending. They do little in most technical areas (like nutrition) because they have small budgets for hiring domestic expertise, preferring to focus on very few areas in which they have some kind of comparative advantage. They do little operations research, make few presentations in scientific meetings, and publish few results of program-relevant research. (The UK’s DFID is a partial exception.)

Thus the Swedish experience on the vitamin A front, while instructive and perhaps unique, is not widely known. The Swedish International Development Cooperation Agency (Sida) had discovered that the VAC program they had been sponsoring in Bangladesh along with UNICEF was not working. Started in the early 1970s, by 1989 distribution campaigns still tended to reach little over half the children in the country. Yet estimates suggested that about 65% coverage was needed before there could be much public health impact (Cohen et al, 1987). (The children who most need such an intervention tend to be in the most isolated and under-served areas and thus are the last to be reached.) Additionally, some 22 million VAC doses were unaccounted for annually and these could do harm, especially if given to pregnant women.

Thus Sida decided to withdraw funding from the VAC program in Bangladesh. It did so cautiously over a few years in the mid 1990s and waited until the World Bank agreed to pick up funding for it. Apparently there nevertheless was a period when funding was inadequate to keep the program going. Sida was then castigated at meetings for “not caring that again 30,000 Bangladeshi children a year were going blind.”  Bloem et al (1995) even claimed in a scientific paper that the Swedish government stopped funding for the program after coming under “political pressure.”

Sida decided to shift their funding to some other approach. Among several alternatives available for reducing vitamin A deficiency in Bangladesh, they chose an innovative, large-scale communication and small-scale horticulture program run by a little-known local non-governmental organization (NGO) called Worldview International. Even today, Worldview’s work is little known in the nutrition sector, because as a communication NGO, it worked with neither the health nor agricultural sectors, but with the Ministry of Education.

Covering every rural household in entire districts (and reaching a total of 9 million people in the districts with the highest prevalence of vitamin A deficiency ) (Greiner and Mannan, 1999), it was able to greatly increase the consumption of high-carotene (from which the body makes vitamin A) foods in the diet of the preschool age children at a cost of US$0.13/capita/year (Greiner and Mitra, 1995). Once its systems were well-developed (which required about 8 years of gradually improving its methods in a few districts), it then required only about 3 years to achieve effective implementation per district. This involved using a range of media and face to face nutrition education activities in villages by “female volunteers” to increase the demand for local high-carotene foods and using these same women to help villagers grow their own. To assist landless families, three seeds each of three varieties of plants that grow on vines (squash, pumpkins and beans) were provided to every household in the district. These foods were then widely planted on rooftops, trellises and even in near-by trees.

Early results from this project were presented in some international meetings in 1993 but the main one of relevance, the International Vitamin A Consultative Group (IVACG), declined to have it presented. Since it received little publicity, the fact that so much was achieved at such little cost was no embarrassment to what at the time turned out to be the beginning of a huge donor-driven push for universal VAC distribution.

However, a finding more damaging to that push was presented at various meetings. Before deciding what alternative approach to support in Bangladesh, Sida had wanted to know what the government and other donors were doing or planning to do to combat vitamin A deficiency. They received the same response from both quarters: a somewhat embarrassed version of “nothing.” After all, there were so many other priorities, and “we have the capsules to fall back on” (Greiner and Ekström, 1989).

Given that VAC programs risked having such a policy blocking effect, it was then suggested at an IVACG meeting (Greiner 1993) that, if requested to support universal VAC programs, donors agree to do so, but request at the same time proposals for projects they could simultaneously fund that would (a) improve diets and (b) monitor dietary quality so that VAC could be gradually phased out when no longer needed. At first this suggestion attracted support. At one meeting, a staff member of the Micronutrient Initiative called for consensus that this three-pronged approach be endorsed.

North America takes over

But the idea was soon nipped in the bud. North American (ie, north of the Rio Grande River) donors had decided that VAC was the only way to go and nothing was to distract from it. (For example, the Micronutrient Initiative was ordered not to spend more than 15% of their funds on any other approach.) At first it was announced that universal VAC was needed in all countries with an infant mortality rate above 100/1000 live births, as this was a simple proxy for countries where vitamin A deficiency was likely a public health problem. But then this was lowered to 70/1000 and finally in 2002 (International Vitamin A Consultative Group (2002)) to 50/1000, greatly increasing the number of countries that “invariably prove to have significant VAD.” The scientific basis originally used to establish 100 as the cut-off point had not substantially changed when these changes were made. One is left with the assumption that the cut-off point was changed rather to fit the increasing availability of donor funding for VAC. Further, it was announced at meetings that VAC was no longer to be referred to as a “short-term” strategy, but should be considered a permanent, routine part of health care delivery, like vaccination.

Up until that time, developing country representatives in meetings commonly stated that they did not want nutrient supplementation programs, but rather long-term solutions that improved the diets of all their people. Such a statement was then commonly followed by a representative of one of the pro-VAC agencies saying something like, “Yes, dietary improvement is important, but what about the exceptional cost-effectiveness of nutrient supplementation programs?”  In response to my repeating the proposal I made at IVACG in 1993, in one international meeting I was asked, “Aren’t you then putting yourself in the position of being a murderer for proposing something that might delay the implementation of universal VAC programs?”

At another meeting where the Sida findings were presented, a UNICEF staff member stated that, although perhaps some mistake had been made in Bangladesh, other governments would not repeat this and in fact were choosing VAC programs because they wanted programs of proven effectiveness. The late Nicholas Cohen, a recognized expert in vitamin A programs, at the time working as a consultant for WHO, countered, “You know that’s not true. Donors offer governments the choice between VAC or nothing. I witnessed that happening just recently in Malawi.”

At one national vitamin A program planning meeting in Tanzania in 1993, government representatives made it clear that they were satisfied with the existing disease-based approach (wherein VAC is targeted only to sick or malnourished children presenting at health centers) and did not want universal VAC. But they later accepted it–no politician will risk turning down any offer of aid, even if it does not fall within his or her priorities—that would risk political suicide. While I commonly heard public statements against the universal VAC approach by representatives of low-income governments in meetings before about 1990, I have heard none dare to oppose VAC since that time.

That universal VAC distribution is a donor-imposed program is further suggested by the fact that those countries like Brazil and India with adequate internal funding and expertise do not implement it universally, but carefully target it to vulnerable areas and groups where they know vitamin A deficiency is a serious public health problem. One report (Micronutrient Initiative, 2009) calls VAC “push driven” rather than demand driven.

Clearly seeing food-based approaches as a threat, VAC proponents and donor agencies began to call them “political” and to relegate them to the latter parts of international meetings. And, handily for them, a 1995 study suggested that carotene from the more low-cost vegetables was much more poorly absorbed than had been previously estimated (de Pee et al, 1995). Presentations of this began to occupy the token space reserved for food based presentations in relevant international meetings. Findings showing, for example, that common tropical fruits improved women’s vitamin A  status as much as beta carotene supplements (keeping in mind that VAC cannot be used for women, Ncube et al, 2001) were ignored, as were findings that deworming greatly improves the absorption of carotene (Persson et al, 2001).

Eerily, decades old statements that typical diets in developing countries doomed their people to protein deficiency were now echoed for vitamin A. IVACG in 2002 stated that ‘It is thus virtually impossible to completely correct widespread VAD by diet alone in developing countries where populations remain dependent on conventional plant-based foods.’ (IVACG, 2002). The same statement increased the amount to be given to infants and to postpartum women (in the first 6 weeks after delivery, when they cannot again be pregnant). VAC and plenty of it was thus finally on the verge of becoming a routinely accepted health sector intervention when a second “fiasco” article was published.

The Great Vitamin A Fiasco

One of pioneers in the field of international nutrition, the late Michael Latham, published in 2010 “The Great Vitamin A Fiasco” (Latham, 2010). He pointed out that most of the 200 million children now receiving megadoses of vitamin A neither have vitamin A deficiency nor suffer from malnutrition. He also pointed out that while the initial clinical trials suggested impact was likely, there have been no impact evaluations published of this enormous intervention, decades old in some countries. Indeed, most of the countries making good progress in achieving the Millennium Development Goal of reducing infant mortality are not among the countries implementing VAC.

Most damningly, Latham cited a recent systematic review (Gogia et al, 2009) and the largest and most recent clinical trial (Awasthi et al, 2007), both of which found that VAC has no measurable impact on young child mortality. He suggested that the most likely reason for the earlier positive VAC findings was that vaccination rates for measles were low at the time these studies were done. Measles is the only disease unequivocally shown to lead to mortality when accompanied by severe vitamin A deficiency.

Latham went on to cite several large studies that VAC fails to have any substantial impact on morbidity from common childhood diseases (Dibley et al 1996; Grotto et al. 2003 and Ramakrishnan et al, 1995). Such findings are hard to explain if indeed vitamin A is so closely linked to mortality. Latham called for a rapid phasing out of universal VAC programs, and their replacement by food-based approaches which “make evolutionary sense, and are biologically, socially, culturally, economically and environmentally appropriate.” They “promote family and community life, provide employment and strengthen local economies, prevent other diseases, and promote well-being.” Latham finished by quoting the 1992 International Committee on Nutrition (ICN): “Supplementation should be progressively phased out as soon as micronutrient-rich food-based strategies enable adequate consumption of micronutrients.” As far as I am aware, twenty years later, no country has even begun let alone concluded such a phasing out process.

Response from the developing countries

From the point of view of nutrition experts in the developing countries, Latham’s article clearly conveyed a message they had been waiting to hear. Beginning with several from India, a stream of letters poured in to support the Fiasco thesis. Reddy (2010) expressed agreement with Latham’s views, saying, “the evidence for the use of supplementary vitamin A for reducing child mortality is unconvincing.” Rao (2010) wrote, “A powerful partnership of pharmaceutical agencies and some international organizations has strenuously tried to promote the massive-dose approach”. Bawa (2010) wrote, “In advocating for food based resources scientists and doctors are advocating for empowering communities: training mothers on nutrition and developing more contact with the families in need. This would be a holistic approach to helping a community heal and grow in healthy ways. Alas, the international aid community is not investing in such approaches.” Gopalan (2010) wrote “taking note of the possible deleterious effects of administering massive doses of vitamin A as a universal programme, summarised below, this approach should be scrapped forthwith.” Sachdev and Kapil (Gopalan et al, 2010) wrote that they and other eminent Indian scientists “have voiced identical concerns, which have been consistently ignored or demeaned by the ‘Vitamin A lobby’. We hope that this commentary from North America will be the proverbial last straw that breaks the camel’s back. Universalisation of the vitamin A supplementation programme represents a classic example of global recommendations framed by a small group of influential experts, rather than by representative and unbiased scientists from populations that have to live with these guidelines.”

Soekirman and several others from Indonesia (Gopalan et al, 2010) decried the loss of balance from the early days when countries were encouraged to develop their own programs. He wrote, “We appreciate Dr Latham’s rousing review of vitamin A deficiency control and the rise to power of the supplementation members of the vitamin A community.” Florencio (2010) of the Philippines asked, “Why retain this intervention which has failed to live up to expectations after decades of implementation and boastful claims…?”

The UN response

Latham’s article may have been seen as one of the reasons for “reforming” the UN Standing Committee on Nutrition, to remove the troublesome non-UN groups from its decision-making. In one of its final inclusive Steering Committee meetings in 2010 (since which, almost nothing has been heard of the SCN—it has held no full meeting since 2008), one of the UN agency representatives expressed his outrage at Latham’s article and demanded an immediate SCN or at least WHO rebuttal. No such has been forthcoming, however. Indeed, the only UN agency to respond in print was FAO, which provided a commentary supporting much of what Latham had written (Boutrif et al, 2010).

Response of the academic coterie

There were no letters to the editor of the journal opposing Latham’s commentary except one from two of the small “coterie” of academics Latham referred to. West and Sommer (2010), calling Latham’s article the only fiasco, wrote “It’s shocking to find that a new journal seeking legitimacy would publish, as its launch, such a meandering, opinionated, unscientific, 28-page diatribe that distorts the evidence on vitamin A and child mortality from over a half-dozen randomized trials reported in peer-reviewed journals, as it attempts to rewrite the history of one of the most successful nutrition-based, child survival strategies in the developing world”.

They later wrote a more detailed rebuttal (West et al, 2010), saying the real fiasco is that “food-based strategies to prevent malnutrition have not yet properly been developed, tested, implemented, taken to scale, and proven adequately to solve the dietary deficits of the world’s poorest populations,” ignoring the fact that VAC’s policy blocking effect, preventing all this happening, was a major reason Latham called widespread donor-driven universal VAC implementation a fiasco in the first place.

Here I summarize some key responses I made to them (Greiner 2010).

1) Even if vitamin A assists the body in fighting infection (West et al’s explanation for its mortality-reducing impact), so do many other nutrients, many of which are commonly provided in food-based interventions. If vitamin A alone has such a huge impact, studies should show that it substantially decreases sickness, as has been shown for measles. Yet West al agree such evidence does not exist. Thus at present we cannot rule out the possibility that achieving high coverage of measles vaccination will largely remove the impact of vitamin A supplementation on young child mortality.

2) Women often suffer from vitamin A deficiency (Professor West himself published a paper from Nepal suggesting that this could have an equally large impact on maternal as on young-child mortality (West et al, 1999)). VAC cannot be given to them due to possible teratogenicity if they happen to be pregnant. The lack of concern about this particular defect of VAC programs by donors, academics and policy makers seems rather unfair if not outright cruel.

3) West et al (2010) cite several studies they claim to be “program evaluations” showing the impact of actual VAC programs (rather than the clinical trials done two decades ago). In each case these cannot actually be called program evaluations. Some merely assume impact based on the results of the initial clinical trials. It is hard to believe that donors who normally insist on good monitoring and evaluation have neglected to do any on such an enormous program that has run for so long—and which could make them look so good if indeed it was proven to have the expected impact.

Industry response

Most of the vitamin A used in VAC programs comes from a very few companies, the largest of which, DSM, has its own NGO, Sight and Life. Its public response has been to publish several papers in its in-house journal (also called Sight and Life) supporting the VAC approach in various ways. Presumably to hedge its bets, it also purchased a rice fortification technology and has provided a million dollar grant to the World Food Programme to promote its use of fortified rice.

Why does VAC sometimes not work?

Michael Latham’s theory implies that VAC will fail to impact on young child mortality during periods when measles is absent (it tends to occur in waves or brief epidemics), or where vaccination has been effective. But there are several other potential explanations for why VAC can be ineffective. It misses many of the most severely affected groups, even when coverage rates are high. Semba et al (2010) point out that some of its apparent lack of impact could be due the fact that in some places those who receive it are those who are less likely to either have malnutrition or to be in families which have suffered child mortality.

Regarding the failure of the two VAC trials in India specifically, Thurnham (2011) suggests that Vitamin A deficiency is so severe that VAC twice a year may be too infrequent to have an impact on mortality. VAC normalizes vitamin A status for only about 2 months for each dose. This theory is supported by the single trial in India having a huge impact by providing small doses of vitamin A weekly instead of large doses semi-annually (Rahmathullah, 1990).

A further complication is that the physiological effects of Vitamin A are still unclear. Inflammation or infection rapidly reduces serum retinol. This promotes the immune system’s pro-inflammatory Th-1 responses. Vitamin A supplements may interfere with and block this response. Perhaps this could explain its apparent effect of increasing respiratory tract infections or diarrhea in some cases (Grotto et al, 2003) and in increasing subclinical mastitis in HIV-positive women (Thurham, 2010).

Prentice (2011) believes the evidence does not even support the argument that the impact of vitamin A on mortality is due to correction of a deficiency. Perhaps it resets the immune system. Until we know why it often seems to work, we can hardly expect to know why it sometimes does not. A recent systematic review (Imdad et al, 2010) included more studies than the Beaton meta-analysis, but came up with a similar 24% reduction in young child mortality with vitamin A supplementation among published studies. However, when it added the (oddly) still unpublished DEVTA study data (Awasthi et al. 2007), the average impact declined to only 12%.

Does Vitamin A supplementation have a future?

One source claims that a typical national VAC program costs $3 million annually (MOST, 2004) and these programs are found in over 100 countries. However, this estimate was based only on program costs. It ignored shared costs and opportunity costs for personnel and equipment that were not available for other purposes because they were being used for the VAC program. Thus VAC joins a long list of vertical interventions that developing countries accept because a donor pays for them, but which end up wresting substantial direct and indirect costs from the host government.  To justify the opportunity cost of VAC, other (quite worthwhile) interventions, such as deworming and treating bed-nets with insecticide have been sought to distribute also on the “child health days” when VAC is distributed.

There are signs that North American donors may want  to start spending the hundreds of millions of dollars now going for VAC elsewhere. These donors have been putting more and more pressure on developing countries to take over VAC funding, though successes have so far have been limited. Indeed, a 2007 USAID-funded report warns that funding for the program will be threatened if host governments are “allowed” to make their own decisions on use of donor funds (Houston, 2007).

That there is reluctance by host governments to fund VAC programs was impressed on me during a World Bank mission in about 2000 to explore what China was doing about vitamin A deficiency. I visited the heads of the Ministry of Health Maternal and Child Health section (along with UNICEF which was supporting VAC distribution in 40 counties). I asked, “Would China be willing to take over the funding of this VAC program if donor support stops?” After consulting with each other, they answered in the elegant Chinese style of putting any potentially embarrassing meaning between the lines, “Anyone who wants to come to China to do something to help our children is welcome.”

Awareness of the need to move toward more sustainable approaches is also increasing, resulting in calls for systems to be established so that VAC can carefully be withdrawn as other approaches succeed (Thorne-Lyman and Fawzi, 2011). The simplest way to achieve this is undoubtedly fortification of staple foods, and I agree with Thurnham (2011) that vegetable oils and rice are the best vehicles available in many settings. However, I suspect this will prove more difficult than expected–because of the existence of universal VAC programs. As the director of PATH’s Ultra Rice project from 2006-8, I discussed vitamin A fortification of rice with policy makers in several countries. None were interested. They were worried that their already heavily dosed children would get an even more excessive dose of vitamin A. This is presumably the reason that the Annecy Accords (IVACG 2002) mention that fortification should only be done with “a population subgroup,” something that is unusual, difficult, and makes impossible the use of common vehicles like rice and vegetable oil, since they are eaten by everyone.

For similar reasons, supplementation programs sometimes specifically mention that they supply children with a “vitamin-A free” multivitamin. Given that I was called a potential murderer for suggesting something that might merely delay universal VAC implementation, stopping it first in order to implement a fortification program could be perceived as a politically risky option.
By the very fact that the universal VAC approach has elbowed its way to the top of health agendas to become so widespread, policymakers will need to be quite inventive to avoid finding themselves in a corner where no one agrees that it can be phased out yet (or how to do it) and yet no one wants to pay for it.

One possible first step would be to shift these programs into disease-targeted programs providing VAC to any child found to be suffering from a range of diseases potentially linked to vitamin A deficiency or from malnutrition. This would have the additional benefit of reducing the harm (Dibley et al 1996; Grotto et al. 2003) that universal distribution may be doing to healthy children who do not need it. Many countries now have such good coverage by primary health care systems that such an approach could well have as much or more impact than universal VAC, without also having a policy blocking effect.

Conclusions

Semi-annual distributions of megadose vitamin A to all young children now take place in parts of over one hundred countries. This is done not to improve their nutritional status but based on the fact that a majority of clinical trials done two decades ago suggested that this would decrease young child mortality. Since that time, though much has changed, no impact evaluation of real life programs has been done to determine whether these expectations are being realized.

Whether or not they reduce child mortality, universal VAC distribution programs are likely doing some harm to children who already have adequate vitamin A status. These programs also inhibit governments and donors from moving toward more sustainable food-based approaches. Because the donor agencies mainly involved (USAID, CIDA and UNICEF) and a small group of US experts have successfully fought to get these programs accepted as routine parts of primary health care (rather than stop-gap approaches, as they were initially called) phasing them out will be complex and possibly politically risky. However, experts from the developing countries on which they have been imposed are increasingly calling for such an effort to get under way. The United Nations Human Rights Council is similarly calling for demand-driven (as opposed to donor-imposed) solutions, even mentioning that “Food systems based on local knowledge and conditions, such as homestead or community gardens, can be a cost-effective way to combat micronutrient deficiency…” (UN Human Rights Council, 2011).

Universal VAC programs are disempowering and create dependency. Food-based approaches build community strength and independent, sustainable community capacity to solve its own problems. Many of us hope the donors are listening and will take action soon.

Addendum: Recommendations for Action

Very few low-income countries are willing to pay for VAC programs themselves. They are also likely to be unwilling to fund careful VAC phase-out programs. Therefore, no real attempt to learn technically and managerially how such a phase-out can best be accomplished is likely until the donors funding universal VAC distribution programs themselves fund such efforts. The following describes how such efforts could be organized.

1. Put in place, perhaps at pilot scale first, various programs designed to raise vitamin A status and tailored to local needs, which could include either:
a. Fortification of a staple food (vegetable oil or rice are probably the best alternatives) is likely to be the simplest, cheapest and most effective. But governments will need convincing to try it. Since overdosing may be a problem, a monitoring system could be established to ensure that excess vitamin A problems are not taking place among the young children getting VAC in the meantime. If overdoses are found to be common, VAC would be phased out (or phased into disease-based approaches, or distribution to people with proven deficiency) more rapidly.
b. Other food-based approaches (nutrition education COMBINED with increasing the availability of food containing vitamin A (or carotene), including home and community gardening; dissemination of fruit tree seedlings; village level solar drying of fruits; increased local production of eggs; increased availability of small amounts of liver). Programs based on animal foods will not need to focus much on nutrition education except where there are local taboos to their use in infant and young child feeding. However, any animal food program must add a third component: addressing the additional food safety needs involved in the production, storage, and home preparation of animal foods.

2. Set up some kind of dietary monitoring program to assess micronutrient status. For food-based programs, Helen Keller International established a very simple dietary assessment tool that was validated for use at community level (Rosen, 1993). However, in some countries one cannot ignore milk (Persson et al, 1999) or breast milk (Persson et al 1998) as that method recommends. If a very commonly consumed fortified food or condiment were expected largely to replace VAC, then perhaps only consumption of that vehicle for the nutrient need be monitored. A monitoring system examining young child vitamin A status a few months after each VAC dose was provided could also be useful. (If it remains high, VAC is no longer needed.)

3. Set up routine decision-making systems, perhaps at district level, for deciding when to phase out universal VAC at that level. The Tanzania Food and Nutrition Centre developed and utilized such a system with Sida funding for shifting from iodized oil capsule distribution to fortified salt (Peterson et al, 1999). Decision making in that case was done at district level every two years using a combination of simple survey and qualitative methods.

References
Awasthi S, Peto R, Read S, Bundy D, Kourellias K, Clark S, Pande V, the DEVTA team. (2007) Six-monthly vitamin A from 1 to 6 years of age. DEVTA: cluster- randomized trial in 1 million children in North India. Results presented at First Micronutrient Forum meeting, Istanbul, April 2007 (available at http://www.micronutrientforum.org/meeting2007/Tuesday/T1445%20Awasthi.pdf).
Bawa J. (2010) Responses to “The great Vitamin A fiasco”. World Nutrition (available at https://wncommentary.wordpress.com/2010/05/03/hello-world/#comments).
Beaton GH, Martorell R, L’Abbe KA, et al. (1993) Effectiveness of vitamin A supplementation in the control of young child morbidity and mortality in developing countries. Final report of the Canadian International Development Agency. Toronto: University of Toronto.
Bloem MW, Hye A, Wijnroks M, Ralte A, West KP, Sommer A. (1995) The Role of Universal Distribution of Vitamin A Capsules in Combatting Vitamin A Deficiency in Bangladesh. Am. J. Epidemiol. 142(8): 843-855
Boutrif E, Thompson B, Amoroso L. (2010) UN agency backs food-based policies… [Letter] World Nutrition 1, 3: 159-173 (available at http://wphna.org/downloadsjuly2010/WPHNA_VitA_letters_July2010.pdf).
Cohen N, Rahaman H, Mitra M, et al. (1987) Impact of massive doses of vitamin A on nutritional blindness in Bangladesh. American Journal of Clinical Nutrition 45: 970-976.
Dibley JM, SadjiminT, Kjolhede CL, Moulton LH. (1996) Vitamin A supplementation fails to reduce incidence of acute respiratory illness and diarrhea in preschool-age Indonesian children. Journal of Nutrition 126, 434-442.
de Pee S, West CE, Muhilal, Karyadi D, Hautvast JG. (1995) Lack of improvement in vitamin A status with increased consumption of dark-green leafy vegetables. Lancet8;346(8967):75-81.
Florencio C. (2010) A view from the Philippines. [Letter] World Nutrition 1, 3: 169-173 (available at http://wphna.org/downloadsjuly2010/WPHNA_VitA_letters_July2010.pdf).
Gillespie S, McLachlan M, Shrimpton R, editors. (2003) Combatting Malnutrition. Washington DC: World Bank and UNICEF.
Gogia S, Sachdev H. (2009) Neonatal vitamin A supplementation for prevention of mortality and morbidity in infants: systematic review of randomised controlled trials. British Medical Journal 338: b919.
Gopalan, Sachdev, Kapil, Soekirman et al. (2010) Responses to The great vitamin A fiasco. World Nutrition 1, 2: 78-119 (available at http://wphna.org/downloadsjune2010/WN%20June%202010%20Correspondence.pdf).
Greiner T. (1993) Prerequisites for the initiation of “universal” VAC distribution: a policy think piece. In: International Vitamin A Consultative Group XV Meeting report “Toward Comprehensive Programs to Reduce Vitamin A Deficiency.” Arusha, 8-12 March, page 91.
Greiner T. (2010) The case for universal supplementation is not well made. [Short communication] World Nutrition 1, 6: 275-282 (available at http://wphna.org/wn_communicationnov2010.asp).
Greiner T. and Ekström C.-E. (1989) Final report to SIDA on Nutritional Blindness Prevention Programme review mission in Bangladesh, March 4-31, 1989 (unpublished).
Greiner T and Mannan MA. (1999) Increasing micronutrient intakes in rural Bangladesh: An NGO’s search for sustainability. In: Scaling Up and Scaling Down: Overcoming Malnutrition in Developing Countries, Marchione T (editor). London: Gordon and Breach, pp. 157-177.
Greiner T and Mitra SN. (1995) Evaluation of the impact of a food-based approach to solving vitamin A deficiency in Bangladesh. Food and Nutrition Bulletin 16(3):193-205.
Grotto I, Mimouni M, Gdalevich, Mimouni, D. (2003) Vitamin A supplementation and childhood morbidity from diarrhea and respiratory infections: A meta-analysis Journal of Pediatriatrics 142: 297-304.
Houston R. (2007) Sustainability of vitamin A supplementation programs. Technical brief to USAID. (available at http://pdf.usaid.gov/pdf_docs/PNADK392.pdf).
Imdad A, Herzer K, Mayo-Wilson E, Yakoob MY, Bhutta ZA. (2020) Vitamin A supplementation for preventing morbidity and mortality in children from 6 months to 5 years of age. Cochrane Database of Systematic Reviews Issue 12. Art. No.: CD008524 (available at http://www.update-software.com/BCP/WileyPDF/EN/CD008524.pdf).
International Vitamin A Consultative Group (2002) The Annecy Accords to assess and control vitamin A deficiency. Summary of recommendations and clarifications (available at http://pdf.usaid.gov/pdf_docs /PNACS105.pdf).
Jonsson U. (2010) Time to return again to holistic policies. [Letter] World Nutrition 1, 3: 165-169 (available at http://wphna.org/downloadsjuly2010/WPHNA_VitA_letters_July2010.pdf).
Latham M. (2010) The great vitamin A fiasco. [Commentary] World Nutrition 1, 1: 12-44 (http://www.wphna.org/downloads/WPHNA_web_commentary_may2010.pdf)..
McLaren DS. (1974) The great protein fiasco. Lancet 13;2(7872):93-6.
Micronutrient Forum. (2009) The 2nd International Meeting of the Micronutrient Forum, 12-15 May, Beijing, China. Sight and Life Magazine 2/2009. (http://www.dsm.com/en_US/downloads/sustainability/SAL_magazine2_2009.pdf).
Micronutrient Initiative (2009) Scaling Up Micronutrient Initiatives: What Works and What Needs More Work? The Innocenti Process. Washington DC: MI.
MOST, USAID Micronutrient Program (2004) Cost analysis of the national vitamin A supplementation programs in Ghana, Nepal, and Zambia: A synthesis of three studies. Arlington, Virginia, USA. (online at http://www.wphna.org/wn_commentary_westklemmsommer_oct2010.asp
Ncube TN, Greiner T, Malaba LC, Gebre-Medhin M. (2001) Supplementing lactating women with puréed papaya and grated carrots improved vitamin A status in a placebo-controlled trial. Journal of Nutrition 131:1497-1502.
Persson V, Greiner G, Islam S, and Gebre-Medhin M. (1998) The Helen Keller International Food Frequency Method underestimates vitamin A intake where sustained breastfeeding is common. Food and Nutrition Bulletin 19:343-346,.
Persson V, Greiner T, Bhagwat IP, and Gebre-Medhin, M. (1999) The Helen Keller International Food Frequency Method may underestimate vitamin A intake where milk is a normal part of the young child diet. Ecology of Food and Nutrition.38:57-69.
Persson V, Ahmed F, Gebre-Mehlin M, Greiner T. (2001) Increase in serum beta-carotene following dark green leafy vegetable supplementation in Mebendazole-treated school children in Bangladesh. European Journal of Clinical Nutrition 55(1):1-9.
Peterson S, Assey V, Forsberg BC, Greiner T, Kavishe FP, Mduma B, Rosling H, Sanga AB and Gebre-Medhin M. (1999) Coverage and cost of iodized oil capsule distribution in Tanzania. Health Policy and Planning 14:390-399.
Prentice AM. (2011) Mechanistic research could help to fine-tune vitamin A-related interventions. Sight and Life Magazine 25(3):48-49.
Rahmathullah L, Underwood BA, Thulasiraj RD, Milton RC, Ramaswamy K, Rahmathullah R, Babu G. (1990) Reduced mortality among children in southern India receiving a small weekly dose of vitamin A. N Eng J Med 323:929-35.
Ramakrishnan U, Latham MC, Abel R, Frongillo Jr EA. (1995) Vitamin A supplementation and morbidity among preschool children in South India. American Journal of Clinical Nutrition 61: 1295-1303.
Rao SP. (2010) Responses to “The great Vitamin A fiasco”. World Nutrition (available at https://wncommentary.wordpress.com/2010/05/03/hello-world/#comments).
Reddy V. (2010) Need for food-based programmes. [Letter] World Nutrition 1, 2: 106-107 (available at http://wphna.org/downloadsjune2010/WN%20June%202010%20Correspondence.pdf).
Rosen DS, Haselow NJ, Sloan NL. (1993) How to use the HKI food frequency method to assess community risk of vitamin A deficiency. New York: Helen Keller International.
Semba RD, de Pee S, Sun K, Campbell AA, Bloem MW, Raju VK. (2010) Low intake of vitamin A-rich foods among children, aged 12-35 months, in India: association with malnutrition, anemia, and missed child survival interventions.Nutrition 26 (10):958-962.
Solon F, Fernandez TL, Latham MC, Popkin BM. (1979) An evaluation of strategies to control vitamin A deficiency in the Philippines. American Journal of Clinical Nutrition 32 (7):1445-53.
Thorne-Lyman A, Fawzi W. (2011) Operations research could help to fine-tune vitamin A-related interventions. Sight and Life Magazine 25(3):47-48.
Thurnham, DI. (2010) Interactions between multi-nutrients, vitamin A, mastitis and HIV. Sight and Life Magazine 24(3):25-31.
Thurnham, DI. (2011) Vitamin A supplementation. Sight and Life Magazine 25(3):38-47.
UN Human Rights Council. (2011) Report submitted by the Special Rapporteur on the right to food, Olivier De Schutter. A/HRC/19/59, December 26. (http://www2.ohchr.org/english/bodies/hrcouncil/docs/19session/A.HRC.19.59_English.pdf)
West KP Jr, et al. (1999) Double blind, cluster randomised trial of low dose supplementation with vitamin A or beta carotene on mortality related to pregnancy in Nepal. The NNIPS-2 Study Group. BMJ. 318(7183):570-5.
West K, Sommer A. (2010) Shocking distortion. [Letter] World Nutrition 1, 2: 105-106 (available at https://wncommentary.wordpress.com/2010/05/03/hello-world/#comments).
West KP Jr, Klemm RDW, Sommer A. (2010) Vitamin A saves lives. Sound science, sound policy. [Commentary] World Nutrition,  1, 5: 211-229. Obtainable at http://www.wphna.org/wn_commentary_westklemmsommer_oct2010.asp

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Comments 9
  • The article is surely revealing, and courageous, thanks Independent Science News ! The story reminds me of how similar approaches are being used for pushing “foods for malnutrition” in children, recommended by “few experts” and same way I was blamed by an international expert Mike Golden to be a “baby killer” in an international meeting on use of ready to use therapeutic foods, when i challenged the approach. Most of the push by UNICEF also use the same argument that children are going to die and those who oppose are therefore not doing justice.
    http://www.ibfanasia.org/gc/Peoples-Charter-for-Food-and-Nutrition-Security.pdf that was outcome of global meeting, recognised that food based approaches and in rights based framework is the way out. Specifically one of the call given was “Ensuring that any food or ingredient introduced in public food and public health programmes undergoes strict holistic independent scientific assessment and is subject to regulation to control marketing. No new chemical, industrial additive or fortified food or therapeutic food should be introduced in the public health and public food programmes till all conditions of providing adequate food and water are in place.” Quick fixes are loved by the donors, and creating a SUN (scaling up nutrition) with focus on stakeholder platforms that includes private sector is another example of the FORCE of UN and PRIVATE SECTOR together and being pushed on developing countries where children are undernourished. No one is spending on water, sanitation, food and support to women for breastfeeding and her own nutrition .

    The politics of donor aid and further based on Market solutions to benefit the corporations is also clearly visible in “new vaccine” market, where in Advance market commitments are being funded by donors to buy a vaccine on cheap price initially and then to be paid later by recipient country and no control on its pricing of vaccines that are not even fully efficacious.

    Hope that good sense will prevail and policy makers of the countries get more power to listen first and then act against such a PUSH !!

  • This is the typical out-of-the-box type article that would probably not pass the guardians of the paradigm in our scientific nutrition literature. But we need out-of the box-thinkers like Latham and Greiner. World Nutrition and Independent Science News have done us a favor.
    The article comes to call for the next logical step after Latham’s concerns have sunk into the minds and the ethos of many of our colleagues. The plausibility of the fiasco is gaining momentum; very few, if any, pieces of the puzzle seem to be missing.
    We are warned that, after a generation of universal VAC, the needed transition is not easy, but indeed to be considered as a priority.
    Paradigms do not evolve; they are overthrown when new evidence comes in. The evidence is now here –at least the evidence of the well-founded doubt.
    Will those of us in the profession and pertinent decision-makers take this call and move?
    There is a lot of power still to be mustered to counter the unconvinced who seem to be…..so few, but obstinate. It would be easier to win this battle in the realm of our scientific community, but with pharma interests (and that of their acolytes) being so entrenched in this discussion, we are in for an uphill yet winnable battle.

  • Great paper. I cannot agree more with your position, Ted Greiner, of course because I share it. In Burkina Faso, we demonstrated in a five-year project that it was possible to increase local production and consumption of crude red palm oil (RPO), the highest and most bioavailable source of provitamin A carotenoids. However we obtained degressive funding from Micronutrient Initiative until there was just nothing to pursue the project, while substantial funding was provided for capsules and for VA fortification of commercial oil. in the same country of Burkina Faso. We publihed the findings, we went around the potential funding agencies, and we submitted proposals when calls for proposals targeted agriculture projects for improving health. “Interesting proposal” was the standard reply, “but we also received several other high-quality proposals”. Yet, we had shown that VA status of mothers and children improved after only two years of project operations involving social marketing, retailing of RPO in the pilot areas; RPO added to school lunch proved as effective as VA capsules; women extracting the oil were supported for setting up a technical platform to improve the quality of the oil while reducing their workload, and they created pre-cooperative groups; these women are now planting dwarf palm trees to secure their supply of red palm nuts. However, rather than scaling-up this successful project, the initiative has remained small-scale whereas RPO could be the VA capsule for most of Africa, as stated quite a while ago by Noel Solomons, a prominent nutritionist. The pilot project achieved VA status improvement, income generation for women extracting RPO and those retailing it, and it contributed to environment protection since palm trees help stabilize river banks. What else could we have done to “sell” the approach? It is David against Goliath…
    English peer-reviewed publications on this topic:
    Delisle H, Zagré N, Ouedraogo V, Tarini A. Marketing of red palm oil for vitamin A in Burkina Faso: a pilot project involving women’s groups. Food Nut Bull 2001; 22:388-94
    Delisle H. Food diversification strategies are neglected in spite of their potential effectiveness : why is it so and what can be done? In: Brouwer ID, Traoré AS, Treche S (eds.). Proceedings of the 2nd International Workshop on food-based approaches for a healthy nutrition in West Africa, 23-28 November 2003. Ouagadougou, Presse Universitaire, 2004 : 303-16
    Delisle H. Potential of red palm oil for the control of vitamin A deficiency in sub-Saharan Africa: Five years of research in Burkina Faso. Sight & Life 2006; 3:22-7
    Zagré NM, Delpeuch F, Traissac P, Delisle H. Red palm oil as a source of vitamin A for mothers and children : Impact of a pilot project in Burkina Faso. Pub Health Nutr 2003; 6: 733-42
    Zeba AN, Martin-Prével Y, Delisle HF. The positive impact of red palm oil in school meals on vitamin A status : study in Burkina Faso. Nutrition J 2006; 5:17 doi:10.1186/1475-2891-5-17.

    Hélène Delisle, Ph.D., professor and director of TRANSNUT, WHO Collaborating Centre on Nutrition Changes and Development, Department of Nutrition, University of Montreal, Canada,

    • Thank you, Hélène Delisle, for making these important comments. I wrote about red palm oil in the FAO/ILSI manual (http://www.fao.org/docrep/X5244E/X5244e00.htm) back in the early 90s, as have many others. As you say, the resulting silence has been deafening.

      Dr. West, in an offline and indirect response to my article, still claims that data on the impact of food-based programs are lacking. The fact is, yours and many other projects show that carotene-rich foods can greatly improve vitamin A status.

      Your experience also provides further evidence that VAC is the “only act in town” that donors are willing to recognize and fund, one more mechanism by which VAC actively hinders the development and implementation of more sustainable approaches.

      Thanks again!

      Ted

  • This is an excellent article putting forward a very balanced viewpoint about how developing countries are loaded with donor driven programmes.
    As far Vitamin A is concerned, there has been an attempt even to suggest it as an effective intervention for neonatal mortality in Asian region. If you recall, the Lancet series on maternal and child undernutrition suggested that neonatal vitamin A supplementation is associated with 21% reduction in mortality in babies under 6 months and included it as a core public health intervention in neonatal period for the Asian region (http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(07)61693-6/fulltext?_eventId=login#bib135). This is interesting to note that the studies based on the findings of which these recommendations were made were either replete with a conflict of interest or not factually referred. Three out of four quoted studies were financially supported by the Sight and Life, Hoffmann- LaRoche, a front organization for the Roche Company which produce and market Vitamin A all across the world. Not only this, one of the study which was conducted in India, was done by the institute which was established with a gift from Task Force Sight and Life, Roche.
    These findings have been contested for several methodological issues, which were highlighted by the one of the co-author of the article, Prof. HPS sachdev. His communication (http://download.thelancet.com/pdfs/journals/lancet/PIIS0140673608607503.pdf?id=afe8b6b6e1926035:-59bef0e0:120ebb80d68:-13101240910244833) which was published in the subsequent issue of the Lancet, highlighted the following objections in the methods of the review process:
    1. With all relevant data from published studies and data from abstracts of two unpublished studies in the public domain, the pooled estimates show no evidence that neonatal vitamin A supplementation has an overall survival benefit during infancy
    2. Such an important recommendation was based on some Asian studies
    3. Relevant—but negative—data from published and unpublished placebo-controlled trials were not included
    4. Unpublished data were selectively cited. A statement providing positive results of a meta-analysis (personal communication by authors of an unpublished study) was added before publication without Prof. Sachdev’s knowledge. However, another large negative unpublished study was not mentioned, even though both the studies had published abstracts in the proceedings of the same conference.

    Taking note of these irregularities, Indian Pediatrics, a peer reviewed scientific journal published an editorial ((http://www.indianpediatrics.net/june2008/439.pdf),), in which the editor said “To conclude, it is essential to act urgently because there might be intense lobbying for initiating newborn vitamin A supplementation in the country. Even UNICEF and WHO may buckle to the pressure of this so called “core intervention”. Utmost caution is warranted against any hurried steps on the basis of this recommendation. Attempts could be under way to commercialize micronutrient malnutrition in the country by presenting incomplete evidence and my plea is that all the stakeholders should be aware of the complete evidence before any decision is taken”.

    The whole story raises several questions which needs answers.
    1.Funding of research trials by the industry to establish their products with the help of the scientific community, many of whom get financial benefits from the companies
    2.Publication of such studies in the reputed journals without taking note of a possible conflict of interest
    3.Use of findings of such studies while formulating recommendations for the public health agencies and policy makers
    4.Manipulation of available research evidence to push certain products in the public health programmes

    This is the way things are moving. There is a need to be vigilant and raise these issues wherever there is an opportunity.

    JP Dadhich, New Delhi, India

  • Great work Ted. My piece may contribute to this discussion too: http://www.freshfruitportal.com/2012/09/12/opinion-biofortification-is-an-obstacle-to-food-justice/ Any comments or criticisms there would be most welcome.

  • Thanks for the article Ted, and for the many references. I note especially your Persson et al 1998 reference, looking at VitA consumed through sustained breastfeeding in Bangladesh. In studied regions “97% of children 12 to 23 months of age, 73% of those 24 to 35 months of age, 32% of those 36 to 47 months of age, and 10% of those 48 to 59 months of age were still being breastfed [21].” http://archive.unu.edu/unupress/food/V194e/ch08.htm I’ve spent some time reading into breastfeeding and these are impressive figures. I was pleased to read “Women in the study area sleep beside their babies and may not remember or be fully aware of all nighttime feedings”, which I think is how an effort could be maintained! The conclusion was that infants and young children are getting a lot of Vit A through breastmilk. So I had a picture of women outputting Vitamin A through a lot of breastmilk, but where is the input? I noted from this article and other references that women can’t consume the donor VitA capsules since at these very high doses they could have a teratogenic effect. So I have an image of constant depletion, and women producing a continuous supply of marginally deficient infants – a steady supply for the pharma industry to cure! Am I seeing this correctly? Was anything being supplied to women, such as beta-carotene capsules?

    I have noted your 2013 piece at the FAO “The amounts [of VitA] in breast milk depend on the mother’s vitamin A status, which
    has been found to be quite low in some rural areas of Africa (Ncube et al. 2001b).” Also “In some cultures some colostrum, an especially rich source of vitamin A, is discarded on the false assumption that it is harmful; in India, about half of the mothers attempt to discard it (Vijayaraghavan 2002).”
    VITAMIN A: MOVING THE FOOD-BASED APPROACH FORWARD http://www.fao.org/fileadmin/user_upload/agn/pdf/Greiner_VITAMIN_A_Final.pdf

    Greiner T and Mitra SN. (1995), seemed to show low rates of night blindness in a poor area of Bangladesh studied, being 1.5%, and 0.7%, noting that these rates did not change as a result of the intervention. I was wondering if some aspects of night blindness may be complicated by other pre-existing conditions that could not be solved in a general community VitA intervention, possibly including non- or partial- participation from the most challenged community members. I wondered about the validity of the ‘VitA deficiency’ criteria. Do you have anything on this?

    • Dear Ms. Love,

      Thank you for these interesting comments. You ask some complex questions. I agree that maternal vitamin A deficiency is almost totally ignored. But I would argue that this is another side effect of the exclusive donor focus on megadose capsules for young children. While there are cases where this has a negative impact on both mother and child, I have not seen evidence of vitamin A levels in breast milk reaching such low levels that frank infant deficiency results. From what I’ve seen in the literature, when vitamin A deficiency is seen in infants, it is due to a failure to exclusively breastfeed, displacing breast milk with other feeds.

      I believe that the reason we failed to find an impact on the rate of nightblindness in the 1995 study was that the background level was already lower than we expected at baseline. We only measured the impact of the 3rd year of the program. The first two may already have had whatever impact the program was going to have. As we found later in Tanzania, high levels of intestinal worms can also be the cause. There it completely reversed the level of serum retinol so that the intervention area was lower even though people ate more green leaves and doing so increased SR. See http://www.tedgreiner.info/?p=408

  • An update: The much-delayed DEVTA study has now come out. Its results, and other recent Vit A developments are discussed in this letter to the BMJ:
    http://www.bmj.com/content/343/bmj.d5294/rr/665130

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