If you’re like most Americans, your level of vitamin D is subpar (under 30 nanograms/mL) if not outright deficient (under 20 nanograms/mL). It is difficult to get enough vitamin D from foods and if you live in the northern states there is not even the possibility of getting enough from the sun (the biggest source of vitamin D). Fortunately, it is now clear how much vitamin D is needed.
Two decades ago, everyone believed that vitamin D’s key contribution to health was the making of strong bones. However, that may now be the least of it as research has demonstrated the nutrients regulatory role in almost every system in the body. Further, vitamin D’s most notably functions actually occur within the brain.
In the brain, researchers have revealed that vitamin D has an array of effects, including stimulating the growth of nerve cells to preserving memory in executive function, all the while clearing out the toxins implicated in Alzheimer’s disease. Vitamin D facilitates memory consolidation by boosting the strength of nerve signals; it stimulates gene expression o f molecules essential to neurotransmission and preserves the myelin sheath around nerve fibers.
Michael Holick, a professor of medicine at Boston University, is one of the leading experts on vitamin D. He says that vitamin D deficiency not only puts older adults at risk for cognitive decline, but it also has “serious long lasting consequences for mental health”. Holick maintains that vitamin D deficiency is widespread among all age groups, and those most at risk are young adults who are consistently indoors, working.
Low vitamin D levels accelerate memory loss. A study that followed 400 older men and women for five years found that those with subpar levels of vitamin D experienced a decline in episodic memory and executive functioning two to three times faster that those with normal levels. Experts on vitamin D also suggest that cognitive decline might be guided by prenatal levels of the nutrient. Studies of prenatal vitamin D deficiency not only impairs later brain functioning but has also been linked to the development of schizophrenia and psychosis.
So the take home is that we need more vitamin D. It is vital for both our physical and mental well-being. Holick suggests that cognitive decline does not start in our later years but builds over a lifetime, thus underpinning the importance of supplementing vital nutrients at all ages. Further, boosting vitamin D levels during pregnancy is highly suggested, taking the best prenatal vitamins is the best option for this; Holick advises that 4,000 IU daily of vitamin D is optimal during pregnancy. Research also suggests that the current recommended value of vitamin D is not enough. The current RDA is 600-800 IU daily depending on age, however experts on the nutrient prescribe 3,000 to 4,000 IU daily.