Vitamin D and Health

6.81 A pilot RCT in India (Khadilkar et al., 2010) investigated the effect of vitamin D supplementation on
size adjusted bone area and BMC in underprivileged adolescent girls (n=50; age, 14-15y) randomised
to receive either vitamin D 2 (7500 µg/300,000 IU) or placebo 4 times/year for 1 year; all participants
also received calcium (250 mg/d). Median (IQR) post supplementation serum 25(OH)D concentration
was 75.2 (64.2-85.5) nmol/L in the intervention group and 28.1 (16.7-34.0) nmol/L in the placebo
group. There was no significant difference between the two groups in bone outcome measures.
Muscle strength and function
6.82 IOM Report: Muscle strength and function in children and adolescents was not considered.
Evidence considered since IOM
Intervention studies
6.83 Ward et al. (2010) examined the effect of vitamin D 2 supplementation (4 doses of 3750 µg/150,000 IU
over 1 year) on muscle function in adolescent girls (n=69; age, 12-14y; 88% of South Asian origin).
Mean baseline serum 25(OH)D concentration increased significantly in the intervention group (18.1 to
56 nmol/L) but not in the control group (17.9 to 15.7 nmol/L). Efficiency of movement increased
significantly (by 5%; p=0.02) in the intervention group. An interaction was also found between
baseline serum 25(OH)D concentration and jump velocity in the intervention group (p=0.02) with
greater change in those with lower baseline concentrations. There were no improvements in muscle
force or power.
Bone health indices
Summary - Children(4-8y) and adolescents (4-17y)
6.84 A systematic review and meta-analysis reported a significant positive effect of vitamin D supplementation on
total body BMC when baseline serum 25(OH)D concentration was < 35 nmol/L. However these findings should
be interpreted with caution because of a number of limitations in the data and because the 35 nmol/L cut-off
was arbitrarily selected based on the distribution of data.
6.85 The majority of subsequent intervention studies did not find a beneficial effect of vitamin D supplementation on
bone health indices in children and adolescents. Out of 5 studies, none reported an effect of vitamin D
supplementation on bone health indices.
Muscle strength and function
6.86 One RCT reported a beneficial effect of vitamin D supplementation on muscle function in adolescent girls with
mean baseline serum 25(OH)D concentration of 18 nmol/L.
Adults under 50y
Bone health indices
6.87 IOM Report: Women of reproductive age were only considered during pregnancy and lactation. No
trial data were available and only 1 cohort study was considered; therefore no conclusions could be
drawn.
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