The sunshine Vitamin, Vitamin D is by far the most beneficial effect of exposure to sunlight. Our body uses UV B ( 290 to 315 nm ) solar radiation to manufacture Vitamin D from a form of cholesterol. Many skin ailments and fungal skin infections can be cured or managed by sun exposure but we feel Vitamin D is the suns most important contribution in our modern lives. The deficiency of Vitamin D in our bodies has long been known to cause Rickets, Osteomalacia and Osteoporisis.
In the last few years numerous research projects and related studies "1" have shown that inadequate amounts of Vitamin D, are suspected to contribute or increase risk of the following:
- breast cancer
- colon cancer
- prostate cancer
- skin cancer ( Ironically as most skin cancers are caused by over exposure to sunlight )
- high blood pressure
- Vitamin D deficiency can cause disease
- cancer retardation mechanisms
- multiple sclerosis
- chronic pain
- seasonal affective disorder
- several auto immune diseases
This places a person in a difficult position as any Suntan Lotion or Sunblock that is endorsed by Dermatologists ( SPF 15 or Higher ), will block out 95% of our bodies ability to produce Vitamin D via our skin. To much sun exposure causes possible skin cancer, and to little causes Vitamin D deficiency which has its own host of problems. In some western countries 50% of the population over 50 is reported to have Vitamin D deficiency. The answer to this question is not to take expensive Vitamin D supplements, were absorption of manufactured Vitamin D differs from person to person. But to safely expose one to the sun for short periods of time without causing permanent skin damage from sun exposure.
What is the required amount of Sun Exposure for Correct Vitamin D production?
The amount of Vitamin D produced from the sun varies from person to person the,
lighter skin colour we have generally the higher amount of Vitamin D our bodies produce from sunlight.
An exposure of 15 minutes of sunlight on your face or arms and legs without sunblock,
is sufficient for the average person to produce enough Vitamin D for 1 to 3 days use ( 1500 to 3000 IU ).
Vitamin D is fat soluble and is stored in our bodies for up to 60 days. This 10 to 15 minute sun exposure a few times a week ,
is typically to short to cause Skin Sun Damage, but is sufficient to maintain a healthy supply of Vitamin D to our bodies.
Note: 15 minutes full body exposure to sunlight will produce enough Vitamin D ( 10 000 IU ) to provide for 10 days recommended dosage for Adults.
You don't have to over-expose yourself to the sun to get the benefits from natural Vitamin D production
Warning: Excessive Vitamin D from multivitamins and Fish Oils can lead to Vitamin D excess related problems.
Do not exceed 2000 IU Vitamin D intake per day. Current research points to a level of 1000 IU Intake as against 600 IU of Vitamin D that was thought to be required a few years ago. However the maximum dosage of Vitamin D has remained the same. Fact: It is impossible to reach excess levels of Vitamin D from sun exposure as An equilibrium is achieved in the skin when longer exposure to UV B simply degrades the Vitamin D being produced as fast as it is manufactured in the skin. Unprotected over-exposure to sunlight does unfortunately lead to an increase in skin cancer.
Notes and References
"1"Sunlight and vitamin D for bone health and prevention of auto immune diseases, cancers, and cardiovascular disease ( Michael F Holick: American Journal of Clinical Nutrition, Vol. 80, No. 6, 1678S-1688S, December 2004 )
About Vitamin D Including Sections: History, Nutrition, Chemistry, Biochemistry, and Diseases. University of California Riverside
Holick MF. Evolution and function of vitamin D. Recent Results Cancer Res 2003;164:3-28.
Chesney RW. Vitamin D: Can an upper limit be defined? J Nutr 1989;119 (12 Suppl):1825-8.
Hayes CE, Hashold FE, Spach KM, Pederson LB. The immunological functions of the vitamin D endocrine system. Cell Mol Biol 2003;49:277-300.