There is an interesting meta-analysis at JAMA Pediatrics about vitamin D supplementation during pregnancy and offspring growth, morbidity, and mortality. Nothing special, standardized methodology and even somewhat expected outcome.
In this systematic review and meta-analysis of 24 randomized clinical trials including 5405 individuals, vitamin D supplementation during pregnancy was associated with a lower risk of infants being small for gestational age and improved growth during infancy without an increased risk of fetal or neonatal mortality or congenital abnormality.
More interesting are the vitamin lobbyists writing the accompanying editorial (Bo Chawes , Klaus Bønnelykke, Hans Bisgaard) who try by nearly every sentence to devalue the findings of the meta-analysis. They are even getting to the point of
no adverse effects have been found
We don’t see things as they are, we see them as we are.