What Do You Lack? Probably Vitamin D
Vitamin D is a group of fat-soluble secosteroids [A, E, and K are the others]…. Vitamin D3 is produced in the skin of vertebrates after exposure to ultraviolet B light from the sun or artificial sources, and occurs naturally in a small range of foods.
When synthesized in the kidneys, calcitriol circulates as a hormone, regulating, among other things, the concentration of calcium and phosphate in the bloodstream, promoting the healthy mineralization, growth and remodeling of bone, and the prevention of hypocalcemic tetany. Vitamin D insufficiency can result in thin, brittle, or misshapen bones, while sufficiency prevents rickets in children and osteomalacia in adults, and, together with calcium, helps to protect older adults from osteoporosis. Vitamin D also modulates neuromuscular function, reduces inflammation, and influences the action of many genes that regulate the proliferation, differentiation and apoptosis [programmed death] of cells
“Fat-soluble” means that these vitamins must be dissolved in fat before they can be absorbed in the bloodstream and carry out their vital functions. Also, any excess of these fat-soluble vitamins are stored in the liver, which means that they are not needed on a daily basis (that doesn’t mean it’s not a good idea to get them daily though).
From the NY Times article:
Every tissue in the body, including the brain, heart, muscles and immune system, has receptors for vitamin D, meaning that this nutrient is needed at proper levels for these tissues to function well.
HOW TO GET IT
Primary Source: the sun (more specifically, ultraviolet B rays absorbed through the skin)
Other Sources: wild-caught oily fish (salmon, mackerel, bluefish, and canned tuna) and fortified dairy products and cereal.
HOW MUCH TO GET
The article quoted some recommended serum levels of vitamin D (>30 nanograms/milliliter), but that means you have to get a specific blood test to determine your current level and a follow-up test to see if you then exceed the minimum level. Instead just follow this simple advice to ensure adequate levels:
Regular, but not excessive, sun exposure during peak sunlight hours (10 AM – 3 PM), unprotected by sunscreen. If you stay outside for longer than about 10-15 minutes, then you can apply some sunscreen.
Can’t I just supplement?
While I do take a supplement, I keep it at a constant but minimum level. The dosage I take would not be enough to meet the minimum suggested serum level alone. Further, if acquired naturally through skin, the body has a built-in cutoff system that prevents excess levels of vitamin D. When enough is made, further exposure to sunlight will destroy any excess. If the source is an ingested supplement, it goes directly to the liver with no cutoff mechanism to prevent excess levels.
In addition to the supplement, I also regularly eat wild salmon, tuna, and other fish that are natural sources of vitamin D.
I still try to make sunlight my main source. As a guy stuck in the office all day, it can be difficult to get outside during peak sunlight hours without getting yelled at! So I just make a concerted effort to get outside whenever possible: walking the dogs, throwing the football with Lauren, or even taking my SHOP workouts outside of the garage and into my driveway or the alley!
CONCLUSION
Get some dang sunlight!
FAVORITE EXCERPTS / MORE FOOD FOR THOUGHT
Although more foods today are supplemented with vitamin D, experts say it is rarely possible to consume adequate amounts through foods.
But the less sun exposure, the darker a person’s skin and the more sunscreen used, the less previtamin D is formed and the lower the serum levels of the vitamin. People who are sun-phobic, babies who are exclusively breast-fed, the elderly and those living in nursing homes are particularly at risk of a serious vitamin D deficiency.
Such low levels could account for the high incidence of several chronic diseases in this country, Dr. Holick maintains. For example, he said, in the Northeast, where sun exposure is reduced and vitamin D levels consequently are lower, cancer rates are higher than in the South. Likewise, rates of high blood pressure, heart disease, and prostate cancer are higher among dark-skinned Americans than among whites.
ADDITIONAL INFO
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