A few months ago we published a truly remarkable study in JAMA neurology that showed older subjects were almost three times more likely to develop dementia if they had low 25(OH) levels.
Now, a group from Arizona headed by Dr. Brendan J. Miller may have found one of the ways vitamin D helps dementia.
Miller Bj, Whisner Cm, Johnston Cs. Vitamin D Supplementation Appears To Increase Plasma Aβ40 In Vitamin D Insufficient Older Adults: A Pilot Randomized Controlled Trial. J Alzheimers Dis. 2016 Mar 31.
In Alzheimer’s disease, plaques of amyloid-B (AB) build up in the brain. This is thought to be due to decades of free radicals and oxidation. If some method was found to remove those plaques, it might help patients with Alzheimer’s. If something was useful in breaking down plaques of AB, then the amount of AB in the blood would increase as AB would be transported away from the brain to be catabolized by the liver.
A total of 19 subjects were randomized into two groups. The treatment group received 50,000 IU of vitamin D3 per week for eight weeks, while the control group received a placebo pill. Both groups had baseline 25(OH)D of around 24 ng/ml. The treatment group’s vitamin D level increased to 51 ng/ml while the placebo group remained unchanged.
Plasma AB increased by 15 ng/ml in the treatment and 13 ng/ml in the placebo group. Significance was p= 0.045; however, when exercise was accounted for, this finding just became a trend. Though, when only examining subjects >60 years of age, AB increased by 18 ng/ml in the treatment group and fell by 3 ng/ml in the placebo group. In older subjects the change in 25(OH)D and the change in plasma AB was significantly correlated (r2 = 0.176).
The authors concluded:
“In conclusion, we show the potential for vitamin D as a primary treatment strategy …”
Should patients with Alzheimer’s be given vitamin D? There are many mechanisms by which vitamin D might prolong their lives. However, whether vitamin D improves the individual’s disease state is yet to be determined. Therefore, further randomized controlled trials evaluating the role of vitamin D in the treatment of AD are needed.