The Sunshine Myth:
Vitamin D and Your Health
Dr. Carolyn Finnegan
Vitamin D Deficiency
We've all heard that we should limit our sun exposure as much as possible to decrease the risk of skin cancer. However, new studies show that a small amount of sun exposure is essential to good health. The sun is our most important source of Vitamin D. It is estimated that more than 50% of both adults and children in the United States are Vitamin D deficient.i
It has been well documented that children need Vitamin D and Calcium for bone health. Rickets was a common problem until Vitamin D was introduced into milk and other fortified foods. The amount of Vitamin D found in fortified foods only provides the bare minimum of what is necessary for a child's skeletal health. Adults need Vitamin D as well. Every cell and tissue in your entire body requires Vitamin D to maximize your overall health and well-being. That's why Vitamin D deficiencies have been associated with autoimmune diseases like Type I Diabetes, Multiple Sclerosis, and Rheumatoid Arthritis. A Vitamin D deficiency also puts you at an increased risk of having a heart attack, stroke and of contracting infections including influenza. Lastly, a Vitamin D deficiency puts you at an increased risk of developing deadly cancers including Prostrate, Colon and Breast Cancer by as much as 50%.ii
Autism and Vitamin D
Autism is also linked to Vitamin D deficiency. In 1989 the American Medical Association's Council on Scientific Affairs warned about the dangers of sun-exposure and advised mothers to "keep infants out of the sun as much as possible." The increase in Autism appears to have begun at the same time. Indeed, most of the graphs showing the rising prevalence of autism over the last 20 years are strikingly similar to graphs showing the rising rates of programs promulgating sun-avoidance.iii While the correlation between Vitamin D and Autism is still speculative, studies do show that autism rates go up when children watch more television or when it rains more. Both issues reduce Vitamin D production. Amish children of Pennsylvania, for example, spend much more time outdoors, and have very low rates of autism. Finally, Vitamin D supplementation in autistic children also improves a number of brain function markers.
Clearly there is no single cause, no single prevention strategy, and no single treatment for autism. However, new research shows that low levels of Vitamin D might be an significant cause of autism. Maternal, infant, and pediatric Vitamin D supplementation as well as limited sun exposure could be an extremely low cost approach to reduce the incidence of this expensive, debilitating, life-long neurological disorder.
How Much Vitamin D is Enough?
The current levels of the recommended daily allowance for vitamin D are 200 International Units (I.U.s) a day. This is because doctors were worried about Vitamin D toxicity. However, with all the current research, most specialists are saying that one would have to take incredibly high levels to become toxic. Specialists are currently recommending 1,500 to 2,000 I.U.s a day for adults along with 5-10 minutes of arms and legs exposure without sunscreen, 3-4 times a week in the Spring, Summer and Fall for light skinned people. Darker skinned people need to be in the sun 5-10 times longer because it is harder for them to absorb the vitamin D due to their built-in protections against the sun. Obese people also need to get twice as much Vitamin D either from supplementation or from exposure as 50% of the Vitamin D ends up in their fat stores and can't get into the blood stream. For children, 1,000 to 1,500 I.U.s a day is recommended. Diet alone will not meet these requirements. No food alone contains enough Vitamin D.
What about Skin Cancer?
Don't throw your sunscreen away. While it is important to get some sun exposure without sunscreen, you want to make sure to apply sunscreen and cover up when you're going to be in the sun for extended periods. Even dermatologists are changing their recommendations. In Australia, there was a study of dermatologists at the end of the summer. 87% of the dermatologists were Vitamin D deficient. Finally, even the Dermatological Society in Australia is recommending small amounts of sun exposure. The American Academy of Dermatology is also now recommending 1,000 I.U.s a day. However, this is not enough and it is unrealistic to expect everyone to take a supplement due to the expense.
Sunlight is free. If you're in a bathing suit, wearing no sunscreen, in the sunlight for 15-20 minutes, it's equivalent to taking 10,000 to 20,000 I.U.s of Vitamin D. To check your base levels of Vitamin D, you can ask your doctor to do a blood test. Healthy blood levels of Vitamin D are 30-100 nanograms/mL.
References:
Nanette Asimov, State's Schools Lack Cohesive Plan For Autism; Autism a "Public Health Crisis" San Francisco Chronicle, July 13, 2008.
Michael Waldman, PhD; Sean Nicholson, PhD; Nodir Adilov, PhD; John Williams, MD, MBA; Autism Prevalence and Precipitation Rates in California, Oregon, and Washington Counties; Archives of Pediatric and Adolescent Medicine; 2008;162(11):1026-1034.
John Jacob Cannell; Autism and Vitamin D; Medical Hypotheses; Volume 70, Issue 4, 2008, Pages 750-759.
J. Moan, A. Dahlback, Z Lagunova, E. Cicarma, Solar Radiation, Vitamin D and Cancer Incidence and Mortality in Norway ,Anticancer Res 2009 29:3501-3509
J. Kragt, B. Van Amerongen, J. Killerstein, C. Dijkstra, B. Uitdehaag, C. Plman, P. Lips, Higher levels of 25-hydroxyvitamin D are associated with a lower incidence of multiple sclerosis only in women, Mult Scler 2009 15:9-15 |
