Researchers were surprised to find that the sperm-filled fluid of men with low blood levels of vitamin D was of no less quality than the semen from men with normal or high vitamin D levels.
Still, a relationship between vitamin D and semen quality can't yet be ruled out. Ramlau-Hansen pointed to some limitations of the study, including the small number of subjects who were actually vitamin-D deficient
Until further studies strengthen and refine the findings, Ramlau-Hansen can only say that more vitamin D "may not be important" for semen quality in men with vitamin levels already in the optimal range.
