The pursuit of optimal brain health is a priority for women of all ages. Ensuring a well-balanced diet with essential nutrients is crucial for supporting cognitive function. In the last four months, we have discussed the science-backed benefits of the B vitamin complex – exploring role of these water-soluble vitamins in metabolism, preventing oxidative stress and protection against brain aging and neurodegenerative diseases. This month, we will turn our focus to vitamin D. 

Vitamin D, often referred to as the ‘sunshine vitamin’ plays a crucial role in maintaining bone health by regulating calcium levels in the body. However, emerging research has uncovered a wealth of evidence supporting the idea that vitamin D also plays a vital role in brain health. Unlike water-soluble vitamins (such as vitamin C and B), vitamin D is a fat-soluble vitamin that can be stored in the body’s liver and tissue and utilized from these reserves in times of need. The most common way to produce vitamin D is through exposure to sunlight. When the skin is exposed to UVB rays from the sun, chemical reactions convert a form of cholesterol into vitamin D which then is converted into a metabolically active form in the kidney. The amount of sunlight needed varies based on factors such as skin pigmentation, time of day, geographical location, and the use of sunscreen. While there are not many natural food sources rich in vitamin D, some foods can contribute to your intake including fatty fish (salmon, mackerel, tuna, sardines), egg yolks, and fortified products (dairy, plant-based milk, breakfast cereals). 

Beyond the benefits of vitamin D to support bone health and immunity, a group of researchers from Tufts University found that the vitamin may also affect our brain’s cognitive function. Published in Alzheimer’s & Dementia, The Journal of the Alzheimer’s Association in 2022, Dr. Sara Booth and her team were amongst the first to investigate vitamin D levels within the brain tissue – finding that higher levels of vitamin D were associated with better cognitive function amongst the participants. The authors collected brain tissue from 290 participants who were part of a larger, ongoing Alzheimer’s research study called the Rush Memory and Aging Project (MAP). At the time of enrollment, MAP participants did not have any underlying dementia and participated in annual neurologic testing. At the time of death, participants in the study agreed to organ donation and underwent vitamin D testing in four distinct regions of the brain. The authors found that higher concentrations of vitamin D were associated with a 25-33% lower risk of dementia or cognitive impairment when measured at the last neurologic test prior to the passing of the participant. 

It is important to note that no structural changes were seen in the brain tissue of those with low vitamin D levels, such as the characteristic misfolded proteins seen in those with Alzheimer’s disease. As such, further research is needed to help clarify the specific mechanisms underlying the protective relationship between vitamin D and cognitive function. 

The field of research surrounding vitamin D is also showing promise in the prevention and treatment of multiple sclerosis (MS). MS is a chronic, progressive and often disabling neurologic disorder that affects the brain and spinal cord. In MS, the immune system mistakenly attacks the protective covering of nerve fibers, leading to inflammation, damage and disruption of the flow of electrical signals along the nerves. This disruption leads to variable symptoms like fatigue, weakness, numbness or tingling, vision problems and issues with bladder and bowel function. A comprehensive review published in Neurology and Therapy in 2018 by Dr. Anthony Reder, an MS expert from the University of Chicago summarizes the protective relationship between vitamin D and MS. The authors note that newer, randomized trials are providing evidence that higher blood levels of vitamin D reduce the risk of developing MS. In a large study involving nearly 200,000 women, the research team found that women who had a higher intake of dietary vitamin D (approximately 700 IU/day) had a 33% lower incidence of MS compared with those with lower intake. Additionally, insufficient vitamin D levels during pregnancy were found to confer an elevated risk of MS amongst children. 

It’s important to note that MS is a highly variable condition, and each person’s experience with the disease can be unique. While there is currently no cure for multiple sclerosis, ongoing research is focused on better understanding its mechanisms and developing new treatment approaches.

In conclusion, the evidence supporting the brain benefits of vitamin D is compelling, highlighting its multifaceted role in cognitive function and neuroprotection. As researchers continue to unravel the intricate connections between vitamin D and the brain, maintaining adequate levels of this essential nutrient is a promising avenue for promoting brain health. It is advisable for individuals to consult with healthcare professionals to assess their vitamin D status and determine appropriate supplementation or lifestyle adjustments for optimal brain health.


Part 1: Vitamin A (to Zinc!)

Part 2: Vitamin B1 (Thiamine)

Part 3: Vitamin B2 (Riboflavin) 

Part 4: Vitamin B9 (Folic Acid)

Part 5: Vitamin B-12

Part 6: Vitamin D