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Vitamin D for athletes December 12, 2013

Mike Merrill, MD drmikemerrill.com. Vitamin D for athletes December 12, 2013. What is vitamin D?. History of rickets. Most severe form of vitamin D deficiency Became prevalent during industrialization 1700's and 1800's Bony deformities (check out your friends' shins) Seizures

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Vitamin D for athletes December 12, 2013

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  1. Mike Merrill, MD drmikemerrill.com Vitamin D for athletesDecember 12, 2013

  2. What is vitamin D?

  3. History of rickets • Most severe form of vitamin D deficiency • Became prevalent during industrialization 1700's and 1800's • Bony deformities (check out your friends' shins) • Seizures • “Animal spirit” didn't make it to the body (Mayow, 1600's) • Didn't occur in tropics. • Cod liver oil helped it

  4. Vitamin D in Evolution • We are African apes • We walked, lost our hair for cooling, developed pigment to prevent sunburn and skin cancer • Subgroups moved north, then lost pigment • Balance between folate destruction and vitamin D production. • In indigenous people, skin pigmentation inversely proportional to yearly UV light exposure • In Europeans, light pigmented evolved 6,000 to 12,000 years ago – rapid selection for this trait at onset of farming

  5. UVA created by George Chaplin and Nina Jablonski, used with permission

  6. UVB

  7. Does meaningful deficiency exist? • Case series, Archives Internal Medicine, 2000 • 5 wheelchair-bound patients with vitamin D deficiency • After replacement, 4 could walk independently, the other 1 with assistance • 4 had resolution of diffuse, body-wide pain

  8. Diagnosis of deficiency

  9. Muscle Pain Skin Cardiovascular Dz Obesity Associations in observational data(note: just associations) • Bone • (Height) • Autoimmune disease • Immune system • Cancer • Brain • Schizophrenia • Depression

  10. Athletic performance • Vitamin D deficiency clearly causes muscle weakness, possibly legs > arms. • You must avoid vitamin D deficiency if you want to be as strong as possible. • Manchester United puts tanning beds over treadmills. • Wintertime is the weak spot. • If you are NOT deficient, you will NOT gain strength by taking extra vitamin D.

  11. How is deficiency treated? • Can't get enough from food • Several pounds mushrooms • 1 pound salmon • Cod liver oil • Whale blubber • Sunlight is OK if you can get it (toxicity impossible) • But probably not enough at our latitude even for very light pigmented people • Just take the stupid pill

  12. Supplement dosing • You probably need 2,000 to 4,000 units a day of D3 during the wintertime. More body weight/more body fat: higher dose. • Ask your doctor for a “25-hydroxy vitamin D level,” NOT a “1,25-hydroxy vitamin D level.” • You want your level at 40 to 50 ng/dl.

  13. Vitamin D types • Cholecalciferol (D3) • Animal form • Works better, oxidizes more slowly • Ergocalciferol (D2) • Really a vitamin D analog • Made from ergosterol in plants • About 50% as potent, reportedly

  14. Toxicity • You probably would have to take 30,000 units of a day for months to have a chance of toxicity. • No evidence, even bad, circumstantial, unscientific, or really old evidence, that 4,000 units a day is dangerous.

  15. Interesting points • Oxidization/decay • T1/2 is 3-6 weeks in air • My experience suggests a waning potency of supplements after bottle opened • I suggest getting a new bottle every month.

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