Vitamin A supplementation needed to prevent blindness in underserved populations

Vitamin A supplementation helps to prevent blindness and child mortality in many developing nations with underserved populations.

According to the World Health Organization, vitamin A deficiency is a leading cause of preventable blindness and death in children and pregnant women. An estimated 250 million preschool-aged children are affected globally by biochemical vitamin A deficiency, 250,000 to 500,000 per year become blind, and half of them die within 1 year.

“Estimates show that Africa and Southeast Asia regions contain the highest proportions of preschool-aged children with biochemical vitamin A deficiency, as indicated by a serum retinol concentration of less than 0.70 mol/L, with Southeast Asia having the greatest number of children and pregnant women affected,” Dhivya Ashok Kumar, MD, a consultant and member of the research faulty at Dr. Agarwal’s Eye Hospital in Chennai, India, said.

Image: Kumar DA

According to 2005 global estimates of vitamin A deficiency, preschool-aged children and pregnant women in 45 countries had moderate to severe night public health problem of blindness and those in 122 countries had moderate to severe vitamin A deficiency, Kumar said.

In India, WHO found vitamin A deficiency to affect 0.8% of preschool-aged children, and the National Nutrition Monitoring Bureau listed vitamin A deficiency as a severe public health problem, with an overall prevalence of 61%, ranging from 52% in Maharashtra to 88% in Madhya Pradesh.

Pakistan was also reported by the WHO to have subclinical vitamin A deficiency.

“According to WHO, Pakistan is a country with severe subclinical vitamin A deficiency,” Farrah Islam, FCPS, FRCS, assistant professor at Al-Shifa Trust Eye Hospital, Rawalpindi, Pakistan, said. “Pakistan has an under-5 mortality of 101 out of 1,000, which is more than India (85), Bangladesh (77) and Nepal (76). However, the morbidity in children under 5 years, suffering from wasting and stunting, is almost similar to that in India, Bangladesh and Nepal.”

“About 72% of our population is living in rural areas with very limited access to health facilities, lack of basic education and poverty; therefore, it is very evident that most of the children remain and suffer undiagnosed,” she said.

According to a survey by the UNICEF West and Central Africa Regional Office, an estimated 42.4% of children 0 to 59 months of age in sub-Saharan Africa are at risk for vitamin A deficiency.

Africa alone accounts for 2.55 million children with signs of night blindness, which accounts for almost half of the children currently affected worldwide, according to WHO reports.

Effects on the eye

Night blindness is the earliest clinical ocular manifestation of vitamin A deficiency; even before that, systemic consequences occur.

An insufficient dietary intake of vitamin A, or retinol, inhibits the production of rhodopsin, the eye pigment that enables vision in lowlight conditions and adjustment to changes in illumination.

Bright light exposure results in the pigment immediately photo- bleaching, but it naturally regenerates within a few minutes, Alfred Sommer, MD, a professor of ophthalmology at Johns Hopkins University School of Medicine and dean emeritus and professor of epidemiology and international health at Johns Hopkins Bloomberg School of Public Health, said at the 2013 American Ophthalmological Society meeting. Photobleaching is the process by which the eye is exposed to bright light, and rhodopsins split instantaneously.

“If you’re bleached because of exposure to bright light, then it’s difficult to regenerate rhodopsin if you’re vitamin A deficient,” Sommer said.

“Greater deficiency affects the normal differentiation of mucus-secreting epithelial cells of the conjunctiva and cornea, which become keratinized and form foamy accretions on the side of the eye known as Bitot’s spots. With further deficiency, the cornea ulcerates and melts away (keratomalacia), and the eye becomes permanently blind,” Sommer said in a follow-up interview.

“As a general or specialized ophthalmologist, everyone should be aware of the early signs of vitamin A deficiency,” OSN APAO Edition Board Member Amar Agarwal, MS, FRCS, FRCOphth, chief surgeon and chairman of Dr. Agarwal’s Eye Hospital, said. “Vitamin A supplementation should be started immediately without any delay.”

Causes and prevention

The primary cause of vitamin A deficiency is malnutrition, Sommer said.

Animal products such as dairy, liver and egg yolks are the only source of preformed vitamin A, and these products are either unavailable or generally too costly for people in developing countries, he said.

Sommer and Kumar said that adequate intake of provitamin A carotenoids, found in dark-colored vegetables, would prevent vitamin A deficiency in older individuals, but Sommer noted that the conversion is inefficient.

“It is virtually impossible for a toddler to consume enough vegetables to satisfy their vitamin A requirement. Most diets, in fact, contain far too little carotene in any case, as people mainly eat inexpensive starches, such as rice, corn, wheat and cassava,” he said.

Pregnancy and lactation can also lead to vitamin A deficiency in women. Kumar said that the Reproductive and Child Health program in India has included the detection and management of clinical vitamin A deficiency in pregnant women as a component under antenatal care.

Treatment

Because breast milk is a critical source of vitamin A, promoting breastfeeding is the best way to protect infants from vitamin A deficiency, according to the WHO. “Early weaning from breast milk can increase the risk of vitamin A deficiency,” Agarwal said.

“In infants, exclusive breastfeeding until 6 months [of age] and proper weaning after 6 months should prevent vitamin A deficiency,” Kumar said.

Because vitamin A is a required nutrient, supplementation is needed upon completion of breastfeeding in countries where foods rich in vitamin A are sparse.

“WHO and UNICEF have long championed improvement of vitamin A status, primarily for the time being by twice-a-year large-dose supplements,” Sommer said.

Due to the administration of vitamin A supplementation by countries, supported by UNICEF, approximately 1.25 million deaths have been prevented since 1998 in 40 countries.

Those in underserved populations generally cannot afford and do not have access to vitamin A supplementation and, therefore, rely on organizations to provide it.

Vitamin Angels, a nonprofit organization that provides nutrients to at-risk populations, encourages local organizations to take responsibility for micronutrient deficiency by creating accessible micronutrient supplies and distribution, according to the website vitaminangels.org.

For US$0.25 per child annually, vitamin A deficiency can be prevented with one dose of vitamin A twice a year, according to an article on the website one.org, an advocacy organization that campaigns against extreme poverty.

Preventive and diagnostic measures are also crucial.

“We regularly evaluate for nutritional status of pediatric-age patients in our center and for vitamin A deficiency,” Kumar said. Malnourished children are referred for special consultation for further management.

In addition, her practice runs regular awareness campaigns on the significance of vitamin A in children and the damaging impact that malnourishment can have on the eye.

“Regular nutritional assessment in school-going children and cre ating awareness among parents about the significance of vitamin A will prevent vitamin A deficiency,” Kumar said.

Vitamin A should be administered immediately to children who are vitamin A deficient.

“Regarding the treatment of vitamin A deficiency, the sooner the better is the best strategy,” Islam said. “Treating vitamin A deficiency at a late stage may decrease mortality but not the morbidity.”

Limited access and compliance

Many countries have not been able to accurately assess the level of vitamin A deficiency because of limitations in storing and transporting biological samples or because laboratory facilities are sparse, according to the UNICEF report A Decade of Progress.

“A lot of effort is required to reach and screen the far,” Islam said.

Compliance can be impeded by religious beliefs or doubts regarding results.

According to Joseph Konde, MD, CEO and president of the Blindness and Visual Handicaps Prevention Programme from the Democratic Republic of the Congo, religious taboos regarding treatment may exist.

“The resistance is there, but it is really getting lesser and lesser,” he said.

Sommer said that, so far, some nutritionists in the global community have been resistant to the administration of vitamin A supplementation for fear that it will not live up to expectations.

Sommer is involved in research and policy projects regarding appropriate age and dosage of vitamin A in children.

“We’ve now completed three randomized trials demonstrating that children should receive a dose of vitamin A within 2 days of birth, which would probably save the lives of an additional half a million children each year,” he said. “But the naysayers again question these startling cost-effective results.”

He said that the WHO recently funded other groups of investigators to replicate these studies, with results anticipated in about 1 year. “A lot of effort is being put in through various NGOs with the help of WHO and UNICEF, yet we are just able to touch the tip of this iceberg,” Islam said.

The relationships between poverty, vitamin A deficiency, measles and childhood blindness are concerning.

According to the United Nations Office for the Coordination of Humanitarian Affairs 2008 report, the immunity boost that vitamin A supplementation provides, which increases resistance to infections and produces red blood cells, contributes to the reduction of mortality from conditions such as diarrhea and measles. In addition, poverty can contribute to malnutrition because it may prevent access to medical care.

UNICEF said that at least 500,000 children become blind every year due to vitamin A deficiency in underserved countries and nearly 70% die within 12 months.

“It is a vicious cycle when you have poverty, and our country is a post-war country,” Konde said. “We need to do more about these interventions, like vitamin A supplementation, which is the most costeffective intervention and action that can be bought to save a child’s sight and life.”

He expressed a desire to partner with other groups to provide treatment.

“We really need to change the picture,” Konde said.

Islam said that health education is one of the primary goals of WHO, UNICEF and other NGOs working in Pakistan. The regular provision of vitamin A supplements should also be a goal because prevention is better than a cure.

“The root cause of all problems in third-world countries is lack of education and economic stability,” she said. “All these problems are interconnected and form a vicious cycle; therefore, resolving such issues needs a sustained and multifaceted effort by local and international agencies.”– by Christi Fox

References:

Barclay AJ, et al. Br Med J (Clin Res Ed). 1987;294(6567):294-296.

Beta-carotene. Mayo Clinic. www.mayoclinic.com/health/beta-carotene/NS_patient-betacarotene. Updated Sept. 1, 2012. Accessed Oct. 21, 2013.

Bhattacharjee H, et al. Indian J Ophthalmol. 2008;56(6):495-499.

Congo: Vitamin A campaign targets deficient children. IRIN humanitarian news and analysis: a service of the UN Office for the Coordination of Humanitarian Affairs. www.irinnews.org/printreport.aspx?reportid=77607. Published April 4, 2008. Accessed Nov. 7, 2013.

Corporate capability statement. Vitamin Angels. www.vitaminangels.org/corporatecapability-brochure. Accessed Nov. 21, 2013.

Global prevalence of vitamin A deficiency in populations at risk 1995-2005: WHO global database on vitamin A deficiency. World Health Organization. whqlibdoc.who.int/publications/2009/9789241598019_eng.pdf. Published 2009.

Gragnolati M, et al. India’s undernourished children: A call for reform and action. Health, Nutrition and Population: the World Bank. siteresources.worldbank.org/HEALTHNUTRITIONANDPOPULATION/Resources/281627-1095698140167/IndiaUndernourishedChildrenFinal.pdf. Published August 2005.

Hornby SJ, et al. Indian J Ophthalmol. 2000;48(3):195-200.

Khan MA, et al. J Pak Med Assoc. 2005;55(2):77-78.

Kraemer K, et al. Preventing blindness and saving lives with vitamin A. One.org. www.one.org/us/2012/10/11/preventing-blindness-and-saving-lives-with-vitamin-a. Published Oct. 11, 2012. Accessed Sept. 9, 2013.

Micronutrient deficiencies. World Health Organization. www.who.int/nutrition/topics/vad/en. Accessed Sept. 26, 2013.

Prevalence of micronutrient deficiencies. National Nutrition Monitoring Bureau. nnmbindia.org/NNMB%20MND%20REPORT%202004-Web.pdf. Published 2003.

Sinha A, et al. Arch Ophthalmol. 2011;doi:10.1001/archophthalmol. 2011.198.

Sommer A, et al. Lancet. 1981;1(8235):1407-1408.

Sommer A, et al. Lancet. 1986;1(8491):1169-1173.

Vitamin A deficiency in Pakistan (VAD). Pakistan Institute of Community Ophthalmology. www.pico.org.pk/content/vitamin-deficiency-pakistan-vad.

Vitamin A supplementation: A decade of progress. UNICEF. www.unicef.org/immunization/files/Vitamin_A_Supplementation.pdf. Published 2007. Accessed Nov. 1, 2013.

For more information:

Amar Agarwal, MS, FRCS, FRCOphth, can be reached at Dr. Agarwal’s Group Of Eye Hospitals and Eye Research Centre, 19 Cathedral Road, Chennai-600 086, India; fax: +91-44-28115871; email: dragarwal@vsnl.com.

Farrah Islam, FCPS, FRCS, can be reached at farrahislam@gmail.com.

Joseph Konde, MD, can be reached at +243-85-5237913; email: kondedr@yahoo.fr.

Dhivya Ashok Kumar, MD, can be reached at Dr. Agarwal’s Group Of Eye Hospitals and Eye Research Centre, 19 Cathedral Road, Chennai-600 086, India; email: susruta2002@gmail.com.

Alfred Sommer, MD, can be reached at Johns Hopkins University School of Hygiene and Public Health, 615 N. Wolfe St., Suite E6527, Baltimore, MD 21205, U.S.A.; +1-410-502-4167; email: asommer@jhsph.edu.

Disclosures: Agarwal, Islam, Konde, Kumar and Sommer have no relevant financial disclosures.

 

 

Do you think golden rice or genetically engineered crops in general could represent a solution for vitamin A deficiency?

Golden Rice can effectively address vitamin A deficiency

Golden rice is a new type of rice that contains beta carotene, a source of vitamin A, and could help to reduce vitamin A deficiency. The International Rice Research Institute is working with leading nutrition and agricultural research organizations to develop and evaluate golden rice as a potential new way to reduce vitamin A deficiency.

The body converts beta carotene in golden rice to vitamin A as it is needed. According to research published in the American Journal of Clinical Nutrition in 2009, daily consumption of a very modest amount of golden rice — about a cup — could supply 50% of the recommended daily allowance of vitamin A for an adult because 25% to 40% of the beta carotene in golden rice shows up as vitamin A in the body.

Because rice is widely produced and consumed, golden rice has the potential to reach many people, including those who do not have reliable access to or cannot afford other sources of vitamin A. For many of the people we want to help, rice is the single most reliably available food, and our commitment is to make that rice more nutritious.

Golden rice is intended to be used in combination with existing approaches to overcome vitamin A deficiency, including eating foods that are naturally high in vitamin A or beta carotene, eating foods fortified with vitamin A, taking vitamin A supplements and optimal breastfeeding practices.

We owe it to those suffering to look for all possible ways to help that are safe and effective. Golden rice holds great potential as an effective and safe way to improve people’s vitamin A status among communities where rice is a staple food, so it is important to continue the research to find out more.

 

Gerard Barry, PhD, is the Golden Rice Network Coordinator at the International Rice Research Institute. Disclosure: Barry has no relevant financial disclosures.

Farmer innovations are key

No, for a number of reasons. For one, there are other natural sources of vitamin A. It is just a matter of propagating these plants and vegetables, which may be just in our own backyards or are being propagated by farmers themselves. Vitamin A deficiency on a large scale and in the context of developing countries such as the Philippines can be correlated to the lack of access to income and productive resources. Farmers, given the right support and resources by government, can be productive and achieve sufficiency at the household level. In turn, they on their own terms would be able to have access to safe and healthy food.

On a broader context, golden rice raises concern on its impact on plant genetic resources and, of course, with farmers’ rights. And there is no conclusive evidence that it is really safe, so precautionary principles should be followed. That is why our court has issued an injunction on the field testing of Bt eggplant, a genetically modified organism (GMO), because we have inadequate regulatory safeguards governing the study, introduction and use of GMOs.

We are not against biotechnology per se. What we are against is the continuing and growing trend of the use of science and technology controlling how we should live and eat and how it supplants traditional knowledge and technology. Over time, farmers have shown that they are the stewards and innovators for agricultural biodiversity and have fed the world from time immemorial. Although golden rice is considered part of a humanitarian effort, it is a misplaced priority, and you cannot help but raise concern about its ultimate goal. Why not encourage and promote farmer innovations, which are adaptive and sustainable?

For this will ensure that we will have healthy and sufficient food on our table.

 

Mario E. Maderazo is the Policy and Communications Coordinator of the Southeast Asia Regional Initiatives for Community Empowerment. Disclosure: Maderazo has no relevant financial disclosures.