A new study from the Northern Medical Program shows that taking a relatively high dose of vitamin D, helps brain function.
Dr. Jacqueline Pettersen compared two groups of healthy adults, one taking high Vitamin D doses (4,000 IU/day) and the other taking low doses (400 IU/day), assessing various cognitive functions before and after treatment. She found that the high dose group performed significantly better on tasks of nonverbal (visual) memory, compared to both pre-treatment and the low dose group. Dr. Pettersen also found that the benefits were even more pronounced among those with lower levels of Vitamin D to begin with.
“This is one of the first studies to demonstrate a positive effect of vitamin D supplementation on brain function in healthy adults,” said Dr. Pettersen, a cognitive/behavioural neurologist with the Northern Medical Program. “While there has been good evidence that Vitamin D improves memory in animal models, research to date has been limited with respect to humans.”
Vitamin D, also known as the ‘sunshine vitamin’, is not produced in the body but must be either synthesized in the skin in response to the sun’s UVB rays, or else consumed through diet. However, there are few good food sources of vitamin D, and at northern latitudes, like Prince George at 54N, there are also not enough UVB rays to help make Vitamin D during several months of the year. Unless you take a supplement during the winter (and possibly the summer as well if you take cover from the sun), you are likely to be insufficient.
“These results have implications for public health,” said Pettersen. “For people living in northern B.C., and other regions which experience extended winter, the findings suggest that they should be supplementing with Vitamin D during the cold weather months, and also taking a dose that is higher than the current recommended daily amount.
“However, we don’t know yet if supplementing with high doses for long periods of time is recommendable, as there are likely other important factors that need to be considered. As part of my ongoing research, I am looking at what roles other nutrients may play in addition to Vitamin D, and how genetics may help some individuals benefit more than others from supplementation.”
- The research study was recently published in the international journal Experimental Gerontology.
- Dr. Pettersen’s study was carried out as part of an 18-week randomized trial with 82 participants who were from northern B.C.
- Vitamin D insufficiency has been estimated to affect one billion people worldwide
- The Institute of Medicine defines Vitamin D insufficiency for bone health as levels less than 50 nmol/L and recommends an intake of 600 IU per day for individuals between one and 70 years of age, while the Endocrine Society and other authorities suggest a minimum of 75 nmol/L, and higher levels for optimal health outcomes.
- The optimal level for cognition is not yet known, but Dr. Pettersen’s study suggests it is higher than recommended cut-off values, with levels averaging between 122 and 130 nmol/L in the study’s high dose group.
- Dr. Pettersen’s research is part of a larger series of ongoing Vitamin D-related studies that she is pursuing, which includes the role of genetics and exploring the balance between vitamin D intake and the intake of other nutrients (some of which may be complementary, or even synergistic) such as calcium, magnesium, zinc, vitamin A and vitamin K2.
