Vitamin D: Let the Sun Shine In….at least a little!
Posted Nov 28 2008 12:03pm
In my last blog I wrote about the critical nutrients for healthy bones, including Vitamin D. But Vitamin D has far more important functions than bone building. Fortunately, the best, most absorbable source of D is shining right outside of your door. Unfortunately, the risk of skin cancer has many people shunning it instead of “sunning”. True it’s the Ultraviolet B or “burning” rays that generate vitamin D on the skin, but it only takes about 15 minutes of exposure three times per week (without sunscreen) in peak sunlight to meet the recommended level. (Note that vitamin D synthesis from pigmented skin takes a bit longer than fair skin).
Beyond the Sun – Other Sources of D
While the best place to get your vitamin D is from a conservative level of sun exposure, depending on where you live the level of sunlight available between October and April usually isn’t sufficient. Furthermore, vitamin D can only be stored in the body for 60 days, so you can’t “stockpile” it in the summer for the winter months. Also, the ability to synthesize vitamin D from sunlight decreases with age, as does the function of the kidneys, which help convert vitamin D to its active form.
Of course you can obtain vitamin D from fatty fish (especially salmon and tuna), egg yolks, beef liver, fortified dairy products and cod liver and fish oils. But if your intake of these foods is limited and/or you avoid the sun, you may want to ask your doctor whether supplementing with vitamin D might benefit you. The recommended minimum intake of vitamin D for adults is 400 IUs and for those 70 and older, 600 IUs. Typically, 2,000 IUs is considered the safe upper limit for adults but recently experts have suggested raising that limit in light of all of the positive research on the benefits of vitamin D. Be sure to talk to your doctor before supplementing with vitamin D at a higher level.
The following are just a few examples of vitamin D’s important functions:
Protects the Bones
Recent research suggests that vitamin D may be as important as calcium in preventing bone loss. It is essential for promoting calcium absorption in the gut and maintaining adequate concentrations of calcium and phosphate in the blood to enable normal mineralization of bone. Vitamin D deficiency in older Americans has been associated with greater risk of hip fractures and higher vitamin D intakes from diet and supplements have been linked with less bone loss in older women in particular.
May Help Beat the Blues
Vitamin D appears to play a role in brain chemistry by boosting serotonin levels. Moreover, deficiencies of D have been linked to certain types of depression, chief among them Seasonal Affective Disorder (SAD), which primarily affects northern hemisphere dwellers during the winter months. It’s not yet clear, however, whether lack of vitamin D leads to SAD or whether SAD is merely exacerbated by a D deficiency.
May Help Prevent Cancer and MS
Studies suggest that vitamin D may protect against some cancers (colon, breast and ovarian). What isn’t clear is whether a deficiency of D leads to an increased risk of cancer or whether increasing intake of vitamin D acts as a preventative measure or both. Researchers have long known that more cases of Multiple Sclerosis (MS) occur in the northern hemisphere and suspected there was a link to sun exposure. Now more evidence is gathering that there may be a specific link between MS and a vitamin D deficiency.
Whether you obtain your vitamin D from the sun, food or supplements, be sure you aren’t “D-enying” your body of this vital nutrient! For more information on how a comprehensive, customized nutrition program can enhance your health, please visit my website at http://www.bewellcoaching.com/nutrition_for_health__performance.