Abstract
Vitamin deficiencies remain major etiological factors in the global burden of disease, especially in low- and middle-income countries. The purpose of this state-of-the-art review was to update current information on deficiencies of vitamins and public health approaches to addressing them. Some stages of life present a higher risk of deficiency than others: risks are higher in pregnant women, children (from conception to young childhood), adolescents, the elderly, and all of the over 800 million people globally who are undernourished. At risk are approximately 125 million preschool children with vitamin A deficiency, as well as sub-populations at risk of deficiencies of folate, thiamin, vitamin B12, niacin, riboflavin, other B vitamins. and vitamin D. Addressing micronutrient deficiencies requires identifying those at risk and then working to prevent and manage that risk. Public health approaches include improved, diversified diets; supplementation; fortification and biofortification; and other supportive public health measures. Historically, as with pellagra and beriberi and, in the last 3 decades, with vitamin A and folic acid, there has been encouraging progress, but much remains to be done.