Vitamin D – Beyond bone health

Vitamin D

One of the fat-soluble vitamins, although technically not a vitamin because it can be synthesized by the skin when exposed to sunlight (Ultraviolet B radiation).

Vitamin D is involved in the regulation of at least 800 genes.

Vitamin D deficiency is common and perhaps the most widespread deficiency in developed nations – estimated 75% of Americans

Role in disease states

  • Osteoporosis (adults) and Rickets (children)
  • Immunity; infection
  • Teeth and Gum disease
  • Cancer – Adequate levels associated with lower risk of breast cancer, colon cancer, and prostate cancer.

Getting Vitamin D

Studies have shown that our bodies use about 4,000 IU (International Units) per day.  Dietary sources account for only 5-10% of that total, so either the rest must come from the sun, or this imbalance results in sub-optimal Vitamin D levels.

  1. Food

  • Far and away, fatty fishes are the best source.
  • The next most reliable source is milk fortified with Vitamin D.

  1. Sun

  • Fair-colored skin – 20 minutes in sun can produce 20,000 IU of Vitamin D. In comparison, a large piece of fatty fish may contain 1,000 IU.
  • Nature’s design: Northern climates have less intense sun but access to fatty fish (salmon, sardines, etc) containing large amounts of Vitamin D.
  • Factors decreasing Vitamin D synthesis: clothing, dark skin complexion, aging
  • Shadow rule: Optimal time of day for sun exposure is when the length of your shadow is less than your height.

  1. Supplement

  • Most people require supplementation, usually in the form of Vitamin D3 (cholecalciferol)
  • How much to take is determined by multiple factors.  Determining the appropriate dose may require measurement of your 25-hydroxy Vitamin D level.

Can one get too much Vitamin D?

Yes, it is possible, albeit very rare.  The safe range of Vitamin D levels (the therapeutic index) for Vitamin D is quite large.

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