IQ, vitamin D and sunlight by Marc Sorenson, Ed.D
IQ and vitamin D levels piqued my interest many years ago. This was because research had demonstrated that animals with low vitamin D levels had poorer neurocognitive function. For example, rats born to vitamin D-deficient mothers have profoundly altered brains at birth. The cortex is longer, the lateral ventricles enlarged the cortex thinner, and there is more cell proliferation. Furthermore, there are also reductions in brain content of nerve growth factor. In addition, similar results manifested themselves with older rats born to vitamin D-deficient mothers.
Other research indicates IQ, vitamin D and sunlight have a connection to cognitive function:
Here are more reasons to believe brain and cognitive function associate closely with IQ, as well as vitamin D and sunlight. The book Embrace the Sun. covers the following facts thoroughly:
- Alzheimer’s disease (AD) and non-Alzheimer’s dementia associate with low vitamin D levels and insufficient sun exposure.
- Autism associates with low vitamin D levels. Bipolar disorder associates with both sun exposure and low vitamin D levels.
- In addition, a study of cognitive abilities as they relate to vitamin D levels shows a considerable difference in vitamin D deficient people. Thus, persons with lowest levels are twice as likely cognitively impaired compared to those with highest levels. Remember that sun exposure raises and optimizes vitamin D levels.
- Another study showed twice as many patients with intellectual disabilities showed D deficiency when compared to normal controls.
Back to IQ
Despite the aforementioned facts and research, I had never seen research that associated IQ in humans to sunlight. Consequently, I searched the literature for years, and have now found my research. A most interesting article on IQ, vitamin D and sunlight recently appeared in the Journal of Nutrition. In this study, the researchers assessed pregnant women for vitamin D levels and then assessed their subsequent offspring for IQ.
The researchers assessed these women’s vitamin D levels in the second trimester of pregnancy.
Offspring of women with low vitamin D levels had lower IQs at the age of 4-6 years. The researchers concluded thusly: “Second-trimester maternal vitamin D positively associated with IQ at 4–6 y, suggesting that gestational vitamin D status may be an important predictor of neurocognitive development. These findings may help inform prenatal nutrition recommendations and may be especially relevant for Black and other dark-skinned women at high risk of vitamin D deficiency.
The bottom line regarding IQ.
Pregnant mothers need to optimize their vitamin D levels, preferably by sun exposure to the skin. It will ensure that both they and their offspring will be healthier and smarter. This is vitally important to black women and other women of color, who have large quantities of skin melanin. This inhibits vitamin D production and may be dangerous for their offspring. IQ, vitamin D and sunlight are important to well-being and happiness. Nevertheless, the researchers observed no IQ differences based on race, but only on vitamin D Levels.
For more information on the health benefits of sunlight and vitamin D, visit Sunlight Institute and read the book, Embrace the Sun. 
Happy sunning!