Welcome to part 5 of our 11-part series exploring evidence-based vitamins and minerals that boost brain health, specifically focusing on their significance for women’s cognitive function. We will break down the emerging evidence and highlight which foods serve as rich sources of these nutrients so that you can find new recipes to incorporate them into your healthy, balanced diet. Let’s delve into our final article on the B-complex of vitamins by highlighting the role of vitamin B12. 

Vitamin B12, also known as cobalamin, plays a key role in DNA synthesis and is involved in the metabolism of every human body cell. It has important roles in the production of myelin – a protein that covers and protects the brain and spinal cord cells. Similar to thiamine and folic acid, vitamin B12 is considered an ‘essential’ vitamin because it is not naturally produced in the body. This necessitates taking enough B12 through dietary sources and supplements to meet our metabolic demands. 

Vitamin B12 is primarily found in animal-based foods, and its natural sources include meats (particularly organ meats, like liver and kidney), fish (notably – fatty fish like salmon, mackerel, trout, and tuna), eggs and dairy products. Many plant-based foods are not naturally rich in vitamin B12; however, fortified foods like breakfast cereals, plant-based milks (soy, almond, oat, etc.), and nutritional yeast frequently have synthetic B12 added to them. With the increasing number of adults turning to plant-based dietary changes, vitamin B12 supplements are also widely available and often recommended for individuals who have difficulty obtaining sufficient amounts through their diet alone.  

In recent years, scientific research has shed light on the evidence-based brain benefits of vitamin B12, emphasizing its role in maintaining cognitive health and preventing neurological disorders. We will explore the research outlining its role in memory and mood regulation. 

Cognitive Function and Memory:

A 2001 article published in the journal Neurology by a team from the Karolinska Institute in Stockholm, Sweden, set out to explore the relationship between levels of Vitamin B9 and B12 with the occurrence of Alzheimer’s Dementia. The authors followed a cohort of 370 healthy older adults to determine whether low blood levels of vitamin B would correlate with a later diagnosis of dementia. All subjects had blood tests at the start of the study to determine their baseline levels of B9 and B12 and were followed for three years with regular cognitive testing. 

Over the course of the study, they found that participants with low levels of vitamin B9 or B12 had, on average, a higher risk of developing dementia. This was most pronounced in adults over age 75 who had better cognitive function at the beginning of the study. These results provide early evidence that the complex of B vitamins might be involved in maintaining memory and cognition as we age and support the rationale for supplementation for disease prevention.

A more recent 2020 article published by Dr. Soh et al. in Medicine similarly investigated whether B12 levels were associated with any degree of cognitive impairment. Based in Korea, the study analyzed the cognitive functioning of nearly 3000 older adults using tests of memory, recall and recognition. Participants also underwent laboratory testing to determine whether they had sufficient blood levels of vitamin B12. 

The researchers found that nearly 15% of all older adults in the study met the criteria for vitamin B12 deficiency and that this deficient group scored significantly lower on nearly all memory and recognition tests. However, when the authors factored in other risk factors for cognitive impairment, including age, level of education, smoking, drinking habits and other medical comorbidities, the association between B12 levels and cognitive function was reduced. This study more realistically shows that while vitamin B12 does not directly cause cognitive decline or memory impairment, it likely is a contributing factor. 

Mood and Mental Wellbeing: 

More recently, the influence of a balanced diet is considered a safe and effective way to improve mental wellness. Nutritional interventions have been found to improve self-reported symptoms of depression, stress and anxiety. This led authors from the Swinburne University’s Center for Human Psychopharmacology to conduct a systematic review of the literature on the effects of vitamin B supplementation on mood and mental health, which was published in Nutrients in 2019. 

Of the 18 studies they reviewed, most reported a positive effect on overall mood for B vitamins over placebo. Vitamin B supplementation had particular benefits on self-reported stress levels, with lower levels reported among those who received additional supplements. While not a replacement for psychology or psychiatric care, nutritional support and dietary optimization represent complementary methods to reduce stress levels and improve mood. 

The evidence supporting the brain benefits of vitamin B12 is compelling, emphasizing its crucial role in cognitive function, memory, and mood regulation. 

Adequate intake of this essential nutrient through a balanced diet or supplementation is vital for maintaining optimal brain health and overall wellness. As ongoing research continues to unravel the intricate relationship between vitamin B12 and the brain, it is clear that prioritizing B12 as part of a healthy lifestyle can contribute to long-term cognitive well-being.


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