Over a 4-year period, elderly men and women were about 1.3 times more likely to experience a “clinically significant” decline in their cognitive abilities if they were suffering from an insufficiency or deficiency in Vitamin D, according to a study in Neurology.
The research was part of the Progetto Veneto Anziani, a study following 1,927 elderly Italians. Vitamin D levels were measured at the beginning of the study along with cognitive function using the Mini-Mental State Examination. Then both were measured four years later. “(S)cores lower than 24 were indicative of cognitive dysfunction, and a decline of 3 or more points on the MMSE over the follow-up was considered as clinically significant,” they wrote. “Analyses were adjusted for relevant confounders, including health and performance status.”
The researchers found that elderly people with a Vitamin D “deficiency” (<50 nmol/L) or "insufficiency" (50–75 nmol/L) "were more likely to have declining MMSE scores during the follow-up than those who were 25OHD sufficient (≥75 nmol/L)." Those with a deficiency were 1.36 times more likely to experience significant cognitive decline and those with an insufficiency were 1.29 times more likely to experience a decline compared to people with sufficient levels. (Abstract) Vitamin D deficiency predicts cognitive decline in older men and women (Toffanello, Elena D. et al. Neurology. Published online before print November 5, 2014. doi: 10.1212/WNL.0000000000001080)
Do elevated bilirubin levels and/or HSV-1 provide Vitamin D somewhere in the body outside of the blood?
Correlation does not prove causality. Maybe folks who appear D deficient are already sick and, as yet, undiagnosed. Maybe this “apparent” deficiency is not the cause of illness but rather another symptom. Does feeding them mega-doses of D, force-feeding us all D in milk, bread, flour, etc. affect the outcome long term? Now, there’s a study I’d like to see.
Actually, use of light therapy, not drugs or supplements, can increase Vitamin D. And I, personnally, find it helpful in the winter.
I’ve seen similar claims being made about vitamin K. It’d be interesting to research it further.