Vitamin D and Health

Study Methods Results Authors Conclusions
Harvey et al (2014)
Selection criteria:
Inclusion: RCTs, cohort studies, case
control studies of pregnant women or
pregnant women and their offspring;
included measure of 25(OH)D
concentration or supplementation with
vitamin D or vitamin D containing food.
Exclusion: ecological and animal
studies, not written in English, did not
measure maternal 25(OH)D
concentration in or immediately after
pregnancy or did not supplement
participants with vitamin D in
pregnancy, or where an outcome of
interest was not assessed.
Outcomes
Primary: Neonatal hypocalcaemia,
rickets in the offspring and offspring
bone mass; maternal osteomalacia
Secondary: Offspring body composition
(incl. birth weight, birth length, head
circumference, anthropometry, small
for gestational age, preterm birth and
later offspring outcomes (incl asthma &
atopy, blood pressure & type 1
diabetes); maternal quality of life (incl.
pre-eclampsia, gestational diabetes,
risk of caesarean section & bacterial
vaginosis).
Birth weight (BW)
9 intervention trials: 3 reported significantly greater BW in offspring of supplemented mothers
19 observational studies (14 cohort; 5 x-sectional); 6 studies reported significant +ve relationship
between maternal 25(OH)D & offspring BW, 1 reported a significant negative association.
Meta-analysis of 3 observational studies found weak positive associations between maternal
25(OH)D & offspring BW: Change in BW per 10% increase in vitamin D: 5.63 (95% CI, 1.11-10.16)
Birth length (BL)
2 intervention trials: 1 reported offspring BL of vit D supplemented women was greater than
that for unsupplemented women; the other reported no association.
12 observational studies (9 cohort, 3 x-sectional): 2 reported significant +ve association between
maternal vitamin D status and offspring BL but neither measured maternal 25(OH)D during
pregnancy; 10 studies found no relationship.
Head circumference (HC)
2 intervention studies: 1 reported significantly greater offspring HC in supplemented mothers; 1
reported no effect of supplementation.
11 observational studies (8 cohort, 3 cross-sectional) – none found association between
maternal 25(OH)D & offspring HC.
Small for gestational age (SGA)
2 intervention studies: both reported no significant difference in SGA risk between vit D
supplemented and unsupplemented mothers.
7 observational studies: 1 reported significant risk of SGA if maternal 25(OH)D