Myths vs facts: B12 and Fruchtbarkeit

Vitamin B12 (cobalamin) is critical for cell division, DNA synthesis, and homocysteine metabolism—all processes relevant to fertility in both sexes. Fact: B12 deficiency can raise homocysteine levels, which may impair egg quality, implantation, and sperm function. Studies link low B12 to recurrent pregnancy loss and male subfertility. Myth: High-dose B12 supplements boost fertility in people with normal levels. There is no strong evidence for this. For those trying to conceive, checking B12 status is reasonable, but megadosing without deficiency is not supported. Vegans and vegetarians are at higher risk for deficiency and may benefit from targeted supplementation. Evidence is moderate—mostly observational, not large RCTs. Caveat: B12 is one piece; fertility depends on many factors.