Take Your Vitamins: Hypovitaminosis D in the Developing World

| April 16, 2012 | 0 Comments

A schematic representation of the major causes of vitamin D deficiency and potential health consequences. Both the causes (risk factors) and consequences of hypovitaminosis D tend to be magnified in the developing world.

Described by the New York Times as “the most talked-about and written-about supplement of the decade,” Vitamin D has recently been shown to play crucial roles in brain, heart, immune system and bone health [1]. As a more complete picture of vitamin D’s importance has begun to emerge, so too have the tragic consequences of vitamin D deficiency in the developing world. With a wide range of dietary, cultural, ethnic, and environmental factors playing major roles in deficiency, hypovitaminosis D (vitamin D deficiency) is fast becoming a top global health priority.  It is imperative that policymakers and global health specialists devise new and more efficient delivery strategies to get this crucial supplement to the developing world.

While the health implications of hypovitaminosis D are still not completely understood, studies have indicated that normal vitamin D levels are required for healthy function of almost every tissue in the body [2].  Aside from bone diseases like rickets and osteomalacia (softening of the bones), the New England Journal of Medicine reports that the two conditions most often connected with low levels of vitamin D are atherosclerosis and diabetes mellitus[2]. Although humans naturally generate vitamin D in the skin when exposed to sunlight, cultural factors constrain sun exposure and dietary sources of vitamin D are often minimal. Dr. Edward Giovannucci of the Harvard School of Public Health writes, “Throughout most of human evolution, when the vitamin D system was developing, the ‘natural’ level of 25-hydroxyvitamin D was probably around 50 nanograms per milliliter or higher. In modern societies, few people attain such high levels.”[1]

In an interview with Harvard College Global Health Review, Dr. Hussein Saadi of UAEA University identifies “individuals with low sunlight exposure,” as the most at risk group for hypovitaminosis D3. Yet despite ample sunshine year-round, developing countries bear the biggest burden of hypovitaminosis D, with shockingly high prevalence ranges between 30–90% [4].  In Asia and the Middle East in particular, homebound individuals, women who wear long robes and head coverings for religious reasons, and people with occupations that limit sun exposure, are unlikely to obtain adequate vitamin D from sunlight. Malnutrition, dark skin (melanin pigment reduces the skin’s ability to produce vitamin D from sunlight) and lack of access to supplements only exacerbate deficiency [5].

While the most straightforward interventions to combat hypovitaminosis D would be to ensure adequate sunlight exposure and a healthy diet that includes natural sources of vitamin D (such as fatty fish), a slew of cultural and socioeconomic barriers constrain the efficacy of such approaches.  Dr. Saadi advocates the use of “vitamin D supplements, especially when [sunlight and good diet] are limited or not feasible.” While some countries have mandates requiring vitamin D-fortified foods, many developing countries do not [3].  Vitamin D supplements are inexpensive. More resources and international attention need to be channeled into providing supplements to those in the developing world. Intervention strategies and policies must be revamped; otherwise, developing nations will continue to bear the unacceptable disease burden of vitamin D deficiency.


Sources:

  1. Brody, Jane E. “What Do You Lack? Probably Vitamin D – NYTimes.com.” NY Times Advertisement. 26 July 2010. Web. 19 Feb. 2012. <http://www.nytimes.com/2010/07/27/health/27brod.html>.
  2. Rosen, Clifford J. “Vitamin D Insufficiency.” The New England Journal of Medicine 364:3 (2011): 248-54. Print.
  3. Saadi, Hussein. “Dr. Hussein Saadi: Vitamin D Deficiency.” E-mail interview. 16 Feb. 2012.
  4. “Arch Intern Med — Sign In Page.” Archives of Internal Medicine, a Bimonthly Peer-reviewed Medical Journal Published by AMA. Web. 19 Feb. 2012. <http://archinte.ama-assn.org/cgi/reprint/167/16/1709>.
  5. “Vitamin D — Health Professional Fact Sheet.” Office of Dietary Supplements (ODS). Web. 19 Feb. 2012. <http://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/>.

 

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Category: NCDs, Online

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