Vitamin D Facts

One of the most critical Vitamin D facts is that it is an important part of any multivitamin, multi-mineral supplementation. But it must be in the proper ratio of Calcium Vitamin D and Magnesium as well as other cofactors.


• fat-soluble vitamin

• essential for calcium and phosphorous metabolism

• required for strong bones and teeth

• along with calcium and magnesium helps prevent Osteoporosis JAMA 2005; 294:2336

Before• deficiency linked to increased risk of many common cancers (colon, breast, prostate, ovarian and esophageal) Urology 2002 and South Med J 2005;98(10) And of course these are the types of cells you want to avoid

• may help with respiratory diseases by increasing lung function Chest 2005;128:3792

• its precursor in the skin, 7-dehydrocholesterol, is converted by sunlight into cholecalciferol (VitaminD3)

• very important to take in supplement form if you are elderly to maintain levels between 30 and 60 ng/ml - lower levels result in very increased risk of cardiovascular disease, cancer, autoimmune diseases, low bone density, osteoporosis, periodontal disease etc. Am J Clin Nutr 2006:18

• Obesity makes it hard to maintain optimum levels Clin Advisor 2007:70

• Obesity linked to Diabetes II and type 2 diabetics have lower serum levels of Vitamin D J Clin Endrocinol Metab2007: 2017

• Above 35 degrees north (so northern half of USA and all of Canada) sun levels so low 1 Nov to 28 Feb that little or no Vitamin D3 is produced naturally in the body J Intern Med 2000:260

• Pregnant or lactating women need 1000 – 2000 IU D3/day especially in winter N or 35 N Engl J Med 2007:357

• Darker skin or sunscreen (SPF 15 and above) reduce synthesis of D3 by 99% J Intern Med 2000:260


No RDA. AI is:

• Adults 200 IU/day

• Teens 200 IU/day

• Children 1-4 years 200 IU/day; 4+ years 200 IU/day

Dosage by Supplements

As Vitamin D3 (Cholecalciferol):

• Adults 600 IU/day (up to 1000 IU in winter North of 35)

• Pregnant or lactating women 1000 – 2000 IU/day

• Teens 400 IU/day

• Children 1-4 years 200 IU/day; 4+ years 400 IU/day


• greatest potential of all vitamins to be toxic

• avoid doses above 1000 I.U./day

• at toxic levels can cause calcium deposits in internal organs, kidney stones and elevated calcium serum levels

More Information

You will find lots more information, including full citations and summaries of studies from medical journals in my book It’s About Health. But you can also continue to surf the 200 free pages of this website for lots of valuable, evidence-based information. It’s About Health

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