Many researchers have concluded that a worldwide epidemic of Vitamin D deficiency exists. Of 28 studies assessing worldwide Vitamin D status, Thailand was the only country that demonstrated a study population with mean serum values above 33ng/ml (1). Vitamin D, being an important hormone in the body with receptors on a wide range of tissues and therefore the body has a minimum requirement for it. Dietary sources of Vitamin D are inadequate to meet daily requirements, therefore the majority of the world requires uninterrupted exposure to UVB radiation from the sun or Vitamin D supplementation. Any factor that interferes with the endogenous or exogenous absorption, formation or transformation of this nutrient, may contribute to deficiency (2,3).
There are a number of barriers blocking adequate amounts of sunlight from reaching the skin. Clothing, dark skin pigmentation, sunscreen, air pollution, cloud cover, time of day, distance from the equator and atmospheric ozone content may interfere with sunlight reaching the skin. Vitamin D deficiency is a concern in Australasia, mainly because exposure to direct sunlight is dissuaded due to risks associated with sun exposure. As we age, our ability for UVB to activate pre-Vitamin D compounds in our body also diminishes (4,5).
Vitamin D is essential for healthy bone formation. Breastfed babies feeding from vitamin D-deficient mothers are at highest risk of defienciency and should be drinking fortified milk. Vitamin D supplementation support healthy levels of this vitamin in both mother and baby.
- Mohr, S.B. et al. Breast J. 2008; 14:255-260.
- Holick, M.F. et al. New Engl. J. Med. 2007; 357:266-281.
- Cannell, J.J. et al. Altern. Med. Rev. 2008; 13:6-20.
- Holick, M.F. et al. Lancet 1989; 2:1104-1105.
- MacLaughlin, J. et al. J. Clin. Invest. 1985; 76:1536-1538.