[First 150 words of article in lieu of abstract]
Fortification of foods and advice on sensible sun exposure are urgently needed. At the turn of the 20th century more than 80% of children living in the industrialized cities of the Western hemisphere had rickets.
Rickets became extremely rare in the United Kingdom, Europe, and United States after it was realized that exposure to ultraviolet light was the major source of vitamin D, and after the fortification of milk and other foods with vitamin D.
At least a billion people worldwide are estimated to be vitamin D deficient, mainly because of inadequate exposure to sunlight and inadequate fortification of food with vitamin D.
Skin pigmentation absorbs ultraviolet light, thereby reducing vitamin D production; this can be a problem for certain racial groups who now live in the Northern hemisphere.
Human breast milk contains very little vitamin D and women with vitamin D deficiency provide no vitamin D for their infant. Such infants will be at high risk of developing rickets if they . . .
Source: British Medical Journal, online June 14, 2008: (336):1318-1319. PMID: 18556276, by Holick, MF (professor of medicine, physiology, and biophysics). Department of Medicine, Section of Endocrinology, Nutrition, and Diabetes, Vitamin D, Skin and Bone Research Laboratory, Boston University Medical Center, Boston, MA, USA. [E-mail: firstname.lastname@example.org]