Myth-buster
Vitamin D supplements taken during pregnancy didn't improve bone structure in children at age 6–7 — across nine separate measurements, none showed a statistically significant effect.
This null result from a double-blind randomized trial challenges the assumption that boosting prenatal vitamin D will meaningfully shape children's bone architecture, though it's among the first studies to look at this specific question, so the picture is far from settled.
In a double-blind trial, 222 pregnant women took 1,000 IU of vitamin D daily or a placebo from the second trimester until delivery. When researchers scanned their children's shin bones at age 6–7, they found no differences in bone size, thickness, porosity, or density between the groups. Every single bone measurement — from cortical thickness to trabecular number to volumetric bone mineral density — came back null, meaning the supplement didn't produce a measurable advantage over placebo on any of these outcomes.
Where this fits in the evidence
This is among the first studies we've indexed on Vitamin D for Increased Tibial Cross-sectional Area — treat it as an early signal until more research accumulates.
The study
- Randomized Controlled Trial (RCT)
- n = 222
- 2026-06
- Bone
This is a plain-language summary of a research finding, not medical advice. Pillser surfaces research signals to help you decide what's worth investigating — always consult a qualified professional before changing what you take.