Fetal bones helped a bit by 1,000 IU of vitamin D – RCT

Positive effect of low dose vitamin D supplementation on growth of fetal bones: A randomized prospective study.

Bone. 2019 Feb 21. pii: S8756-3282(19)30070-5. doi: 10.1016/j.bone.2019.02.022.

Vafaei H1, Asadi N1, Kasraeian M1, Shahraki HR2, Bazrafshan K1, Namazi N3.

* Adding 1,000 IU vitamin D while pregnant did not help much (no surprise) – RCT Jan 2019 * 1,000 IU of Vitamin D while pregnant helped a little bit – RCT Dec 2016 * Less bone mass at age 9 if low vitamin D during pregnancy and childhood – Lancet 2006 * Less child bone if mother lacked vitamin D – Dec 2010 * Note: The study on this page only considered fetal bone, not infant nor child bone --- Adding >4,000 IU daily helps a lot more than bones Healthy pregnancies need lots of vitamin D has the following summary {include} Note: The abstract on this page does not appear to indicate when Vitamin D supplementation began --- 1. Ensure a healthy pregnancy and baby - take Vitamin D before conception

The effect of vitamin D supplementation on growth of fetal bones during pregnancy is unclear. The aim of this study was to assess the effect of low dose vitamin D supplementation during pregnancy on bony anthropometric aspects of the fetus. In this prospective randomized trial, 140 patients were divided into two equally matched groups according to age, 25(OH)D level, exercise, and dietary intake.

Then 1000 IU per day vitamin D supplement was given to the intervention group while the control group received placebo. Then crown-rump length (CRL) and femur length (FL) during the first trimester and humerus and femur lengths as well as their proximal metaphyseal diameter (PMD), midshaft diameter (MSD) and distal metaphyseal diameter (DMD) in the second and third trimester were measured using ultrasonography technique. Finally, no significant difference was observed for CRL (p = 0.93). Although FL was not statistically significant in the first trimester (p = 0.54), its measurement in the intervention group and the control group in the second (28.87 ± 2.14 vs. 26.89 ± 2.08; p ≤0.001) and the third (65.31 ± 2.17 vs. 62.85 ± 1.94; p ≤0.001) trimesters was significantly different.

Femoral PMD, MSD, and DMD measurement increased more in the intervention group in comparison with the control group with P values <0.05.

HL measurement in the intervention group and the control group in the second (28.62 ± 1.94 vs. 27.23 ± 2.08; p ≤0.001) and the third (61.29 ± 2.84 vs. 59.85 ± 1.79; p ≤0.001) trimesters revealed significant differences.

Humeral PMD, MSD, and DMD measurement increased in the intervention group in comparison with the control group with P values <0.001 for all.

It is suggested to prescribe low dose vitamin D (1000 IU per day) from early pregnancy with possible increment in length and diameter of femur and humerus bones of the fetus.