Enhancing supplementation of vitamin D among pregnant women could have far-reaching implications on the bone health of whole societies. That was the conclusion drawn from a study conducted in Iran on the impact of low-dose vitamin D supplements on fetal bone development.1
Vitamin D is important to several developmental processes involving early cell differentiation and maturation, with significant correspondence to the development of immune-based diseases such as thyroiditis, cancer, and cardiovascular disease (CVD) later in life. In pregnancy, vitamin D plays a major role in the development of the musculoskeletal system. As pregnant women are at highest risk of vitamin D deficiency, a group of investigators from Iran decided to evaluate the impact of early vitamin D enhancement on the bone development the baby.
The study, published in the journal Bone, reported by Vafaei and colleagues in a February issue of Bone, was a prospective, randomized trial of 68 women aged 20-35 years, in the early stages of pregnancy given 1000 IU daily of vitamin D, compared to 62 age-matched pregnant women given placebo. The intervention started at 2 weeks following absence of menstruation and continued up until the final gestational sonogram at 34 weeks.
Supplementation was associated with significantly greater length of the fetal femur as measured by sonography in the 2nd and 3rd trimesters compared to placebo, as well as increased growth to the proximal metaphyseal, mid shaft, and distal metaphyseal sections of both the femur and humerus. While increases were observed in humerus length, these were not statistically significant. The overall crown-to-rump length was not significantly altered by vitamin D intervention.
These findings suggested that vitamin D supplementation in early pregnancy improved fetal bone health, and according to the authors, may have particular importance in parts of the world where growth stunting or osteoporosis are especially prevalent.
1. Vafaei H, Asadi N, Kasraeian M, et al. Positive effect of low dose vitamin D supplementation on growth of fetal bones: A randomized prospective study. Bone 2019 Feb 21;122:136-142. doi: 10.1016/j.bone.2019.02.022. [Epub ahead of print]