Editorials

Deficiency of sunlight and vitamin D

BMJ 2008; 336 doi: http://dx.doi.org/10.1136/bmj.39581.411424.80 (Published 12 June 2008) Cite this as: BMJ 2008;336:1318
  1. Michael F Holick, professor of medicine, physiology, and biophysics
  1. 1Department of Medicine, Section of Endocrinology, Nutrition, and Diabetes, Vitamin D, Skin and Bone Research Laboratory, Boston University Medical Center, Boston, MA, USA
  1. mfholick{at}bu.edu

    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 industrialised cities of the Western hemisphere had rickets.1 2 Rickets became extremely rare in the United Kingdom, Europe, and United States after it was realised that exposure to ultraviolet light was the major source of vitamin D, and after the fortification of milk and other foods with vitamin D.2 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.1 3 4 5

    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 are exclusively breast fed. Rickets is the most overt sign of severe vitamin D deficiency in Europe—around 1-5% of children with vitamin D deficiency have skeletal signs of rickets and probably 10-25% of adults with vitamin D deficiency have symptomatic osteomalacia.

    Vitamin D deficiency causes secondary hyperparathyroidism and increases …

    Sign in

    Free trial

    Register for a free trial to thebmj.com to receive unlimited access to all content on thebmj.com for 14 days.
    Sign up for a free trial

    Subscribe