Dr. John Campbell is “totally convinced” that high-dose vitamin D supplementation would prevent many cases of dementia, particularly Alzheimer dementia, which is 75% of all dementia cases. He takes 4,000 IU of vitamin D/day plus 100 mcg of vitamin K2. Unclear to me if that’s year-round or only in fall and winter, when there’s less sunshine in the northern hemisphere. I assume it’s oral vitamin D3 (there are several types of vitamin D). Dr. Campbell didn’t say why he takes the K2. Click for a brief review of K2. In contrast to his vitamin D dose of 4,000 IU/day, U.K. health authorities recommend a tenth of that — 400 IU — in autumn and winter.
Several observational studies link higher risk of dementia with blood levels of vitamin D that are deficient or insufficient. Blood levels of 25-hydroxy-vitamin D under 25 mg/ml are particularly linked to dementia. Dr. Campbell admits that it’s difficult to prove that adequate vitamin D supplementation would prevent Alzheimer dementia.
Steve Parker, M.D.
Diabetic Mediterranean Diet 