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How much daily vitamin D should you get?

May 5, 2011 12:00:00 AM PDT
Many health experts were stunned when the Institute of Medicine suggested only a slight increase in the recommended daily allowance for vitamin D. Studies link vitamin D to helping a host of diseases.

There's no shortage of sun in southern California, yet experts say we have a big shortage of vitamin D in our bodies.

"Actually right now the stats show that 70 to 80 percent of Americans are vitamin-D deficient," says nutritionist JJ Virgin.

Due to aging, if your skin is dark, if you wear sunscreen or spend most of your time indoors.

Vitamin D is known to help with bone health, and countless studies show its effects are far-reaching.

But the Institute of Medicine's recent recommendation to raise the dose from 400 to 600 international units (IUs) has experts like Jonny Bowden scratching their heads.

"Vitamin D has a relationship to 100 different documented diseases," says Bowden. "To think we could get all we need from a 600 IU capsule to do all the myriad things that vitamin D does is just insane."

"Strong bones is like the tip of the iceberg for vitamin D," says Virgin. "You look at its impact on diabetes and insulin sensitivity, this is a big one. Mood. Gut health, heart health, cancer. And biggest of all, immune system."

Both experts feel a dosage to better fight disease would be at least 2,000 to 3,000 IUs. Especially since taking higher amounts hasn't shown to be toxic.

"There is not one single piece of evidence anywhere, and you can go to PubMed and look in the National Institute of Medicine library. Not once piece of data ever, ever published for research that shows that there is any damage to a human being taking dosages of up to 10,000 IUs a day," says Bowden.

Keep in mind that fortification in food is minimal, so it's unlikely you'll get enough from diet.

That leaves your prime vitamin D sources as a pill or through sun exposure. But with skin cancer a concern many feel stepping up supplementation is a better way to go.

Further studies and information:

  • 70-80 percent of Americans are vitamin-D deficient
  • Attaining optimal blood levels level of 45 ng/dl typically requires about 3000-4000 IU a day of vitamin D3 (6 times current recommendations).
  • Achieving blood levels of 45 ng/dl (toxic is considered 250 ng/dl) would results in 400,000 fewer premature deaths per year including a reduction of cancer by 35 percent, type 2 diabetes by 33 percent, and all cause mortality by 7 percent (http://www.ncbi.nlm.nih.gov/pubmed/15989379)
  • Studies show that vitamin D deficiency increases the risk of influenza 11-fold (1100 percent) (http://www.ncbi.nlm.nih.gov/pubmed/15042122) and taking vitamin D reduces the risk by 42 percent (http://www.ncbi.nlm.nih.gov/pubmed/18298852)
  • The economic burden due to vitamin D insufficiency in the United States is $40-$53 billion per year from cancer, heart disease, diabetes, influenza, autoimmune disease, depression, fibromyalgia, and other disorders
  • Dr. Jonny Bowden blog on government report on vitamin D