Vitamin B12 and Fertility Is Becoming A Hot Topic

The relationship between vitamin B12 and fertility is becoming a hot topic in reproductive health. As we well know vitamin B12 supports our bodies functioning at a deep cellular level. 1 What many people are not aware of is the potential of our favorite vitamin in supporting optimal reproductive health.2 We’ll explore research that makes the case that maintaining B12 levels may be essential for the smooth functioning of reproductive organs in both men and women and for being able to carry a baby to term both naturally as well as with assisted reproductive treatment. 3,4,5

The Link Between B12 and Fertility in Men

The possible link between vitamin B12 and fertility in men is well documented. When a man is vitamin B12 deficient the health of male reproductive organs may become compromised, possibly leading to less than optimal sperm. 4 Researchers have shown in both animal and human studies how vitamin B12 may possibly assist male reproductive organs accomplish:

  • a reduced level of inflammation causing semen impairment
  • an increase in the efficiency of spermatozoa in energy production
  • reductions in the harmful build up of reactive oxygen in the spermatozoa
  • a beneficial higher value of nitric oxide production
  • a lessening of homocysteine toxicity in the spermatozoa

The net effect is essentially a healthier environment in the reproductive organs positively influencing sperm count, motility and overall sperm quality. This is of course beneficial for successful reproduction. The extent to which vitamin B12 is directly responsible for these positive effects continues to be the focus of research. We are excited to see what further clinical research yields on the topic.

Vitamin B12 Deficiency and Premature Ejaculation, Yikes!

Another correlation that has been the subject research is vitamin B12 deficiency and premature ejaculation, abbreviated PE. Vitamin b12 deficient men have been shown to have a markedly higher rate of PE than those whose vitamin levels are optimal. 5 It’s worth noting that these researchers were careful to isolate depression as a variable to the correlation between low B12 and PE. While more work needs to be done, the current research leads to speculation that the vitamin B12/PE link is neurobiological, having biochemical element. Again, we are looking forward to further research in this area.

This unfortunate condition causes a raft of psychosomatic reproductive issues, the least of which being potential embarrassment and a consequent avoidance of new partnering relationships. 6 Obviously if one develops a pattern of avoiding sex out of anxiety over performance issues like PE then the whole issue of fertility doesn’t get to first base (no pun intended).

Deficiencies in B12 and Fertility in Women

Not surprisingly men aren’t the only ones who may experience reproductive problems due to B12 deficiency. One study found a strong correlation between vitamin B12 and fertility in women. It’s well documented that women who have lower than normal B12 levels are more likely to suffer from both miscarriages and the inability to conceive generally. 7

Low B12 levels may:

  • Alter the blood profile such creating the conditions for miscarriage
  • Inhibit regular ovulation
  • Hinder insertion of the egg disrupting fertilization
  • Disrupt healthy maturation of the egg

Fertility research related to women and B12 goes back nearly thirty years. An often referenced case study reports of a women experiencing problems conceiving responding extremely well to 1000mcg of vitamin B12 being added to her treatment protocol. 8 As mentioned, many of the studies to date are of a correlative nature but they do suggest a strong connection between adequate vitamin levels and successful ovulation. 

We should take care here to note that prior to undertaking any sort of supplementation women should consult with their treating physician. Optimum levels of supplementary vitamins are highly individual and require treatment specific to an individual. 1

Vitamin B12 and Assisted Reproductive Technology (ART)

Of further interest on the topic of vitamin B12 and fertility are the conclusions of researchers at Massachusetts General Hospital’s Fertility Center. These researchers looked at a variety of fertility factors when analyzing blood samples of women receiving assisted fertility treatment with a particular attention on folate and vitamin B12 levels. 9 The results of the study were dramatic: 

  • Test subjects with folic acid blood serum levels at the top of the scale had one and a half times the chance of live birth in contrast to those in the lower 25% of the sample
  • Test subjects with blood serum vitamin B12 levels in the top 25% of the scale had over twice the probability of experiencing a live birth in contrast to those in the lowest 25% of the range
  • These results were determined after multi variable adjustment in the analysis providing a more reliable indicator of vitamin B12’s relevance in fertility than many earlier studies/case reports on the subject

What strikes as particularly interesting about these findings is that none of the subjects were technically outside the normal range when their folate levels were tested and only three of the subjects showed vitamin B12 deficiency. The question then becomes why a such a large difference in successful births between test subjects at the top and bottom ends of the range when almost all were within the medically accepted normal levels of blood serum vitamin B12? The answer to this question currently exists outside of the current research on vitamin B12 and fertility but further work is being done and we look forward to updates.

Should Everyone Take B12 to Support Fertility?

The above is a brief treatment of the potential usefulness of vitamin B12 in reproductive health. While much of the research is correlative there has been some thorough work done, particularly in the area of assisted reproductive treatment. These breadcrumbs show that there’s likely a tie between adequate vitamin B12 intake and fertility in both men and women.

One thing we can say for certain is that these results, while interesting, are not prescriptive. Anyone considering supplementing their vitamin B12 levels should do so under the guidance and care of their doctor.

We look forward to keeping you posted on how the research continues to develop on this topic.



  1. National Institutes of Health – Vitamin B12 Fact Sheet
  2. Prevalence of Low Serum Cobalamin in Infertile Couples, Pront et al.
  3. Impact of preconceptual multiple micro-nutrient supplementation on female fertility, Schaefer et al.
  4. Vitamin B12 and Semen Quality, Saleem Ali Banihani
  5. Relation between blood vitamin B12 levels with premature ejaculation: case-control study, Kadihasanoglu M et al 
  6. Impact of Premature Ejaculation: the psycholigical, quality of life, and sexual relationship consequences, Rosen et al
  7. Vitamin B12 Deficiency, Infertility and Recurrent Fetal Loss, Bennet et al.
  8. Vitamin B12 Deficiency and Infertility: Report of a Case, Sanflippo et al
  9. Association Between Serum Folate and Vitamin B12 and Outcomes of Assisted Reproductive Technology, Gaskins et al.
Leave a Reply

Your email address will not be published. Required fields are marked *