Evidence check: B12 in the context of Fruchtbarkeit

The role of vitamin B12 in fertility is not fully established by strong evidence. B12 is crucial for cell division, DNA synthesis, and nervous system function – all processes relevant to reproduction. Some observational studies link low B12 levels to infertility, recurrent pregnancy loss, and poor sperm quality. However, the evidence is mixed: not all individuals with low B12 experience fertility issues, and supplementation does not guarantee improved outcomes. A blood test (holotranscobalamin or MMA) is recommended before high-dose supplementation. B12 is water-soluble with a very high safety margin, but unnecessary high doses should be avoided. Overall, the evidence is moderate: plausible biological mechanisms and some human data exist, but large randomized controlled trials are lacking. Caveat: Fertility is multifactorial; B12 is just one piece of the puzzle.