What do depression, chronic fatigue and cancer have in common? Recent research indicates they are all linked to Vitamin D deficiency. According to the National Health and Nutrition Examination Survey(NHNES), 50-78% of Americans are Vitamin D deficient. An alarming statistic, but not at all surprising, considering the amount of information warning us of the dangers of the sun. A study of Vitamin D by the Center for Disease Control and Prevention states “people with limited sun exposure, obese people, children, older adults and people with dark skin are at risk of Vitamin D deficiency.” Though it can be absorbed from food sources like fortified foods such as milk and yogurt, fatty fish, and supplements such as Cod Liver Oil, researchers widely acknowledge that the best source of Vitamin D comes from the sun, in the form of UVB rays. While sun protection is common sense, excessive use of sunscreen can actually be harmful to our health. In his book, The Vitamin D Solution, Dr. Michael F. Holick writes “just as we require a little fat and salt for survival, we need the sun in moderation too; for sun exposure is our best source of vitamin D.” In fact, our bodies are designed to absorb Vitamin D from sun exposure.
Often referred to as “The Sunshine Vitamin”, Vitamin D is actually a hormone produced in the skin, that aids in the absorption of calcium and phosphorous. It is vital in the prevention of a mind-boggling number of ailments. The CDC states “increased intake of Vitamin D may reduce the risk of various cancers, diabetes, and heart disease”. The 2005-2006 NHNES Survey linked Vitamin D deficiency in adolescents to “a significantly increased risk” of common allergies such as ragweed and peanuts; Another study found that “vitamin D deficiency may be linked to airway inflammation, decreased lung function and poor asthma control; vitamin D supplementation may help improve asthma symptoms. Vitamin D is also thought to play a role in immune function, which may benefit patients with allergic asthma.”
The National Osteoporosis Foundation and International Osteoporosis Foundation say that most people need 5-10 times the daily recommended dose of Vitamin D; approximately 800-1000 IU, daily. Other studies recommend twice as much. The Vitamin D Council , a non-profit group dedicated to the education and treatment of Vitamin D deficiency, advises that the amount of sun time needed to produce sufficient Vitamin D is half that required to cause a sunburn. There are many factors in determining how much sun we need; age, geographic location, time of year, and skin tone are all considerations. Generally, anywhere from 15 minutes (for pale skin) to 2 hours (for dark skin) daily. Taking your individual factors into consideration, a good rule of thumb when sunbathing is to look at your shadow. The shorter it is, the more likely you are to be producing Vitamin D.
Sources: National Institute of Health; Dietary Supplement Fact Sheet; http://ods.od.nih.gov
Center for Disease Control and Prevention, National Report on Biochemical Indicators of Diet and Nutrition- Vitamin D; Office of the Director, Public Health Grand Rounds 8/19/2010, www.cdc.gov
Sandhu MS, Casale TB “The role of vitamin D in asthma”; http://www.ncbi.nlm.nih.gov
Dr. Michael F. Holick Ph.D, M.D. The Vitamin D Solution, www.drholicksdsolution.com
Vitamin D Council, How to get you Vitamin D, www.vitamindcouncil.org