Do Vitamins B6 & B12 Increase Testosterone? (A Look at the Studies)

Summary: There is no evidence to suggests that vitamin B boosts testosterone levels among humans, however, studies on rats have shown positive results. I certainly would not require either of these ingredients in any testosterone boosting product nor would I take them individually to increase my T levels. See the top vitamins for men here.

Vitamins B6 & B12 Increase Testosterone

Full Analysis:

People are becoming increasingly more willing to take supplements and multivitamins happen to be the most popular category. Vitamin B6, a water-soluble vitamin is involved in glucose metabolism, lipid biosynthesis and production of essential chemicals like neurotransmitters.

Chemically vitamin B6 is called pyridoxine, and pyridoxal five phosphate is its biologically active form. Dietary intake must meet the complete vitamin B6 requirements of the body as our body cannot synthesize this critical vitamin.

Vitamin B6 deficiency leads to health problems in the cardiovascular system, skin, nervous system and immune functions. Studies are describing the effect of vitamin B6 supplements on the reproductive system and hormones. It is responsible for modulating the hormonal secretions from the pituitary gland and steroid hormones. Scientific reports on the impact of administering vitamin B6 in humans and rats are summarized here.

Vitamin B6 deficiency leads to low blood testosterone levels in rats

Study: Male rats were induced with vitamin B6 deficiency by feeding on a vitamin deficient diet for four weeks. Vitamins B6 deficiency in test animals was ascertained by measuring the vitamin levels in the blood. After four weeks of treatment, blood samples were collected for estimating testosterone levels and prostate tissues were collected by sacrificing the animals.

Result: Authors observed low serum testosterone levels in vitamin B6 depleted rats, but the levels of luteinizing hormone remained unaltered. Prostate tissue analysis revealed high testosterone concentration and testosterone was found mainly localized in the nucleus of the cells. This localization was observed as the testosterone receptors were exclusively retained in the nucleus. Vitamin B6 is probably responsible for recycling the receptors (that bind testosterone) from nucleus to cytosol and lack of vitamin led to receptor localization.

Conclusion: Vitamin B6 deficiency in male rats leads to the reduced synthesis of testosterone.


Very high doses of vitamin B6 have no effect on testosterone levels in rats

Study: High doses ( 250 -1000 mg per kg body weight) of vitamin B6 were injected in male rats for 2 and 6 weeks. At the end of treatments, sperm counts plus the weights of the testes, prostate gland and epididymis were taken, and levels of key enzymes were assayed. Blood testosterone levels were quantified in all the treatment groups at the end of the study.

Result: In all the treatment groups there was a decline in reproductive function parameters like sperm. However, the testosterone levels remained unchanged.

Conclusion: High dosages of vitamin B6 does not alter the blood testosterone levels in rats.


Vitamin B6 important for brain development in infants

Study: A survey was undertaken on infants and pregnant women with vitamin B6 deficiency.

Result: Infants with deficiency showed behavioral abnormality and compromised adaptive behavior. Pregnant women with low vitamin B6 levels gave birth to babies with lower than average weight that eventually leads to developmental delays and poor cognitive abilities.

Conclusion: Vitamin B6 is critical for human brain development, and pregnant ladies must be encouraged to consume a diet rich in vitamin B6.


Vitamin B6 does not alter the levels of growth hormone and prolactin

Study: Tolis and co-workers designed this study on nine subjects with galactorrhea (milky discharge from nipples) but with regular and increased prolactin levels. All the subjects were administered vitamin B6 and post-treatment the hormone levels were assessed.

Result: Vitamin B6 therapy did not impact growth hormone and prolactin levels. There was no improvement in galactorrhea or resumption of menses in any of the subjects after two months of vitamin B6 intake.

Conclusion: Vitamin B6 supplementation does not support regulating the levels of hormones like prolactin.


Animal studies on vitamin B6 suggest its decisive role in enhancing testosterone levels. However, there are no human clinical reports directly indicating the testosterone enhancing role of vitamin B6. There are scientifically validated studies linking the vital function of vitamin B6 in brain development, restoring normal thyroid function, facilitating normal absorption of nutrients and strengthening immunity in humans. Vitamin B6 requirement is met by the dietary intake of cereals, eggs, fish, milk, carrots, potatoes and green leafy vegetables like spinach.

Another important vitamin of the B complex group is Vitamin B12. Chemically is known as cobalamin and it is one of the most prominent vitamins consumed as a supplement. This vitamin is present in non-vegetarian diet like meat and deficiency leads to pernicious anemia, neurological disorders, and fatigue.

Vitamin B12 helps in managing fertility, improving immunity and strength. Although there are no scientific studies directly implying the role of Vitamin B12 in increasing testosterone levels its role in pregnancy is well documented.

Vitamin B12 improves semen parameters in subfertile males

Study: Isoyama and co-workers conducted this clinical investigation on 26 subfertile men with the hypothesis that Vitamin B12 supplementation for 4 to 24 weeks at a concentration of 1500 micrograms per day can improve semen parameters. At the end of study total sperm count, motility, morphology was recorded. Levels of hormones like the luteinizing hormone, follicle stimulating hormone, and testosterone were quantified in serum.

Result: Authors observed an improvement in semen parameters like sperm count, motility and morphology. The levels of testosterone, luteinizing hormone and follicle stimulating hormone remain unchanged.

Conclusion: Vitamin B12 helps in restoring male fertility but does not affect testosterone levels.

Source :


Vitamin B6 and B12 supplements support essential physiological functions in the body including a critical role in fertility and cognitive development. There is no concrete scientific evidence emanating from human clinical studies to support a direct role of these vitamins on testosterone levels. Studies on rats have shown an upward shift in testosterone levels on vitamin B6 treatment. These supplements are useful in maintaining general good health for individuals with a history of certain chronic diseases that are linked to the malabsorption of vitamins.