Serum levels of vitamin D are positively associated with sperm motility, suggesting a role for this nutrient in human sperm function, researchers reported in Human Reproduction (2011;26:1307-1317).

In a study of 300 Danish men from the general population, those with vitamin D deficiency had a lower proportion of motile, progressive motile, and morphologically normal spermatozoa than did men with high vitamin D levels.