Vitamin B6 is strongly associated with significant improvements in long term memory in older adults, as well as in short term memory in younger adults.
Vitamin B6 is associated with lower levels of homocysteine and methylmalonic acid, which are biomarkers associated with cognitive decline.
Vitamin B6 is a naturally occurring compound safe to consume -- typical dosage for young healthy adults should be 1.3-2 mg/day.
Vitamin B6, also known as pyridoxine, pyridoxamine, pyridoxal, pyridoxal phosphate, pyridoxal-5'-phosphate, PLP
The three major forms of Vitamin B6 are pyridoxine, pyridoxal, and pyridoxamine.
Figure 1. Chemical structure of vitamin B6.
Vitamin B6 is found in meats and poultry (e.g. chicken, fish, tuna, salmon, milk, cheese), vegetables (e.g. spinach, carrots, beans), and grains (e.g. bran, wheat, brown rice).
After conversion to its active form, vitamin B6 can carry certain physiological effects: increase dopamine levels, reduce fatty acid synthase activity, increase prolactin, potentially increase growth hormones.
Vitamin B6 for (20 mg pyridoxine HCL daily for 12 weeks) yielded a significant improvement in performance on a long term memory storage test in elderly men (age 70-79; n=38).1
Vitamin B6 supplementation (75 mg/day for 35 days) was associated with increased performance on short term memory tasks, namely the word recall task, in a double-blind,randomized, placebo-controlled trial, with greater effects in the younger adults (mean age 25; n=56) compared to older adults (mean age 75; n=75).2
Vitamin B6 (3 mg/day for 4 months) led to lower levels of serum homocysteine and methylmalonic acid compared to baseline levels before treatment, and there were also increases in memory including identifical forms test (5% improvement), synonym test (1.3% improvement), digit symbol test (3% improvement), Thurstone's picture memory test (8.6% improvement) and figure classification test (9.2% improvement) in a study with 209 subjects.3
Vitamin B6 correlated with approximately 30% lower levels of homocysteine, which is a biomarker linked with vascular dementia, which typically involves memory loss (n=1684).4
Figure 1. Supplementation with vitamin B6 and B12 is associated with decreases in levels of inflammatory biomarkers for vascular dementia such as homocysteine, thromboxane and isoprostane.
Vitamin B6 over a 3-year period was associated with improvement in executive function, as measured by the Figure Copying Task component of the Mini Mental Status Examination, in a study of 321 aging men (see figure 2). Higher dosages generally correlated with greater improvements, with the most effective dosage being 3.1mg/day.5
Figure 2. Supplementation with vitamin B6 over a prolonged span was correlated with improvements in the figure copying score, a measure of executive function, in elderly adults.
The Mayo Clinic recommends 20 mg of Vitamin B6 per day for optimal cognitive performance.
Consider taking vitamin B6 supplements if you are at risk for deficiency or may require more than the average diet allows. For example, if you are on a vegan diet that has difficulty getting B vitamins, or if you are an older individual over the age of 50.
Rare in healthy people, minor side effects include: nausea, vomiting, stomach pain, headache, tingling, drowsiness.
Approved as a dietary supplement component under provisions of the Dietary Supplement Health and Education Act of 1994.
Avoid doses of over 100 mg per day. Excessive dosages greater than 300 mg per day can potentially lead to nerve damage, but it is rare.
Deijen, J. B., Van der Beek, E. J., Orlebeke, J. F., & Van den Berg, H. (1992). Vitamin B-6 supplementation in elderly men: effects on mood, memory, performance and mental effort. Psychopharmacology, 109(4), 489-496.
Bryan, J., Calvaresi, E., & Hughes, D. (2002). Short-term folate, vitamin B-12 or vitamin B-6 supplementation slightly affects memory performance but not mood in women of various ages. The Journal of nutrition, 132(6), 1345-1356.
Lewerin, C., Matousek, M., Steen, G., Johansson, B., Steen, B., & Nilsson-Ehle, H. (2005). Significant correlations of plasma homocysteine and serum methylmalonic acid with movement and cognitive performance in elderly subjects but no improvement from short-term vitamin therapy: a placebo-controlled randomized study. The American journal of clinical nutrition, 81(5), 1155-1162.
Clarke, R., Harrison, G., & Richards, S. (2003). Effect of vitamins and aspirin on markers of platelet activation, oxidative stress and homocysteine in people at high risk of dementia. Journal of internal medicine, 254(1), 67-75.
Tucker, K. L., Qiao, N., Scott, T., Rosenberg, I., & Spiro, A. (2005). High homocysteine and low B vitamins predict cognitive decline in aging men: the Veterans Affairs Normative Aging Study. The American journal of clinical nutrition, 82(3), 627-635