Modern lifestyle and diet have made the "d" in the vitamin D stand more for deficient than for anything else. The 2003 National Institute for Health (NIH) conference on vitamin D reported "a growing prevalence of vitamin D insufficiency/deficiency in the U.S. population." Previous concerns over vitamin D toxicity along with a modern sun-phobic America are probable causes of this growing trend towards a lack of something good.
Growing concerns over skin cancers and aging skin have forced many of us out of the sun and into the dark about vitamin D. Dramatic increases in sun protection are suspiciously coinciding with decreases in blood vitamin D levels. But is this correlation really that mysterious? Not if one knows that sun exposure is the body's main source of vitamin D production. The Vitamin D Council website states that "the high rate of natural production of vitamin D3 cholecalciferol in the skin is the single most important fact every person should know about vitamin D..."
Vitamin D And The H1N1 Virus
Vitamin D may be a misnomer. Because our bodies can produce vitamin D by action of sunlight on our skin, most scientists consider it more of a hormone than a vitamin (Murray; 1996:39). Nonetheless, recent research is increasingly confirming the important role that this hormone/vitamin may be playing in the health of our country. Very recent studies may even show that it is protective against the H1N1 virus as well as a treatment for fighting this dreaded flu.
It has long been known that a deficiency of vitamin D can cause rickets in children and osteomalacia in adults. But more importantly, the Vitamin D Council website reports that a deficiency of this vitamin "plays a role in causing seventeen varieties of cancer as well as heart disease, stroke, hypertension, autoimmune diseases, diabetes, depression, chronic pain, osteoarthritis, osteoporosis, muscle weakness, muscle wasting, birth defects, and periodontal disease. Some scientists even argue that exposure to the sun may even help prevent deadly forms of skin cancer, like melanoma."
Vitamin D From The Sun
As natural production of vitamin D from the sun is our most important source of this valuable substance, how much sun do we need? Recent research indicates that you need about 4,000 units of vitamin D per day (currently there is insufficient evidence to establish an RDA for vitamin D). According to the Vitamin D Council website, most of us make 20,000 units of Vitamin D after 20 minutes of exposure to the sun (sans sunscreen lotion). Therefore, exposing a large percentage of the skin to 15 - 20 minutes of sunlight (avoiding sunburn) would supply most of the needed supply of this vitamin. During the winter months, or for persons avoiding the sun for other reasons (ie, aging effects), there should be supplementation. Many health experts believe that cod liver oil is a good source of vitamin D during the winter. Vegetables are typically low in vitamin D, yet are highest in green leafy vegetables (Murray 1996:39).
Don't Overdo It
Over-supplementation of vitamin D can also lead to toxicity. "Increased blood concentration of calcium..., deposition of calcium into internal organs, and kidney stones are some of the characteristics of vitamin D toxicity" (Murray 1996:42). Care should be taken when supplementing with Vitamin D. Nonetheless, given the current trend towards deficiency of this supplement, the Vitamin D Council website claims that taking 2,000 units per day is safe for most individuals. Ordering a 25 hydroxy vitamin D test from your physician can be very helpful in determining dosage of the vitamin.
As the field of science and medicine grows, we may see more of this mixed-message type of recommendation occurring. However, it is the test of time that will reveal the truth about our bodies and how they function optimally. In the case of vitamin D, we sort of "threw the baby out with the bath water." As we continue to discover the importance of this seemingly simple vitamin, let us not waste time in implementing what we already know. Do not be afraid to spend a few moments a day in the sun without any sunscreen. And if you will be in the sun for an indefinite period of time, ensure any products that you use are safe to be absorbed by your skin. Remember that the liver needs to process those substances and remove them from the body along with everything else it has to do.
So it's not so bad to take a walk on the sunny side of the street!
Many people with chronic conditions are showing up low in Vitamin D. It may be necessary to supplement with vitamins to get the levels back up to healthy ranges. If you'd like to know more about Vitamin D testing and supplementation, sign up for a FREE Supplement Consultation.
Murray, Michael. Encyclopedia of Nutritional Supplements. New York: Three Rivers Press, 1996.