Link between vitamin D, dementia risk confirmed (sciencedaily)

[McCamy Taylor]

7. Association is not causality.

People who get out in the sun more may be more active, i.e. they may be less likely to have dementia.

On a related note, up until 1960, people took cod liver oil every day. It had vitamin D, A and omega-3-fatty acids. In the 1960s, we dropped the cod liver oil and started drinking Vit D fortified milk. Could part of the reason for our recent increase in heart disease be the loss of the omega-3-fatty acids from our daily regimen? Cod liver oil was used by Europeans for hundreds of years. The Norse used it as long as a 1000 years ago to prevent rickets from their low winter sunlight.

Nowadays, you have to worry about toxins in fish liver, so be careful if you decide, as I have, to give cod liver oil a try again.

Now, for a possible biochemical explanation of why low Vit D might cause dementia. Low Vit D leads to elevate parathyroid hormone which causes you to take calcium from your bones and excrete it in the urine. That extra calcium circulating in the blood stream has been shown to speed up the formation of coronary artery disease and hardening of the other arteries, presumably by irritating the linings of the blood veseels. So, low Vit D can contribute to stroke which can contribute to dementia. But the study does not prove this, just tends to confirm this.

Also, low Vit D and elevated PTH weaken the bones and contributes to osteoporosis.