Vitamin D and Health

Table 25: Meta-analyses of RCTs on effects of vitamin D supplementation on muscle strength and function in adults ≥ 50y
Study Methods Results Conclusions
Muir et al (2011)
Selection criteria:
Inclusion: RCTs of supplemental vitamin D or
associated metabolite, +/- Ca, with a placebo or
standard treatment arm; adults ≥ 60 y; physical
performance measures of muscle strength, gait or
balance measured at baseline end of study.
Exclusion: Inclusion of an exercise intervention
Outcome measure
Muscle strength, gait and balance.
13 RCTs; mean age 78 ± 4.1 y; 7 studies in community dwelling adults,
Postural sway: (3 RCTs: 2 RCTs vit D & Ca vs Ca, 1 RCT vit D only)
Vit D supplement doses – 1 RCT 1,500 µg D2 single dose, 2 RCTs 20 µg/d D3.
Standardised mean difference of -0.20 (95%CI -0.39,-0.01) p=0.04, I 2 = 0%
Timed up and go test (3 RCTs vit D & Ca vs Ca)
Vit D supplement doses (daily) – 1 RCT 10 µg D3, 1 RCT 20 µg D3, 1 RCT 25 µg D2 .
Standardised mean difference of -0.19 (95%CI -0.35,-0.02) p=0.03, I 2 = 0%
Knee extension strength (3 RCTs: 2 RCTs vit D & Ca vs calcium, 1 RCT vit D only)
Vit D supplement doses - 1 RCT 1,500µg D2 single dose, 1RCT 20 µg/d D3, 1 RCT 25
µg/d D2 .
Standardised mean difference = 0.05 (95%CI -0.11, 0.20) p=0.04, I 2 = 0%
Supplemental doses of 20-
25 µg/d suggest beneficial
effects on muscle strength
and balance. An effect on
gait was not
demonstrated.
Stockton et al (2011)
Selection criteria
Inclusion: RCTs in human adult participants. All forms
and doses of vitamin D supplementation =/- Ca
compared with placebo or standard care.
Exclusion: Not reported
Outcome measure
Muscle strength.
17 RCTs; n=5072
Grip strength (7 RCTs – 5 RCTs vit D & Ca, 2 RCTs vit D only); vit D doses, 10-25µg
D3
SMD = -0.02 (95%CI -0.15,0.11) 25OHD>25 nmol/L
Proximal trunk and upper limb strength (1 RCT – vit D & Ca); vit D dose – 20 µg/d
D3
Bench press: SMD = -0.23 (95% CI -0.66, 0.19) baseline 25(OH)D > 25 nmol/L
Lateral pull downs: SMD = -0.32 (95% CI -0.75, 0.10) baseline 25(OH)D >25 nmol/L
Knee strength (7 RCTs – 4 vit D & Ca, 1 vit D only); vit D supplement dose – 10-20
µg/d D3, 150,000 µg D3 (single dose), 7500 µg D2 (single dose)
Knee extension strength: SMD = 0.10 (95% CI -0.02, 0.29) 25(OH)D > 25 nmol/L
Knee flexion strength: SMD = 0.10 (95% CI -0.21, 0.41)
Leg press (2 RCTs – vitamin D & Ca): vit D dose – 20-25 µg/d D3
SMD = 0.05 (95%CI -0.26, 0.39)
proximal lower limb strength
Overall: SMD = 0.1 (95%CI -0.01, 0.22)
Baseline 25(OH)D < 25 nmol/L (2 RCTs): SMD = 3.53 (95% CI 2.18, 4.85)
Vitamin D did not have a
significant effect on muscle
strength in adults with
baseline 25(OH)D >25
nmol/L. A limited number
of studies demonstrated
an increase in proximal
muscle strength in adults
with 25(OH)D < 25 nmol/L.
Beaudart et al (2014)
Selection criteria
Inclusion: RCTs in English (1966-Jan 2014), control
group comparable to treated group; muscle strength,
mass or power measured before & after intervention
in both groups.
Exclusion: Reviews, non-randomised trials, animal
studies, no placebo/control group, vit D used as part
of complex nutritional supplementation regimen.
Outcome measure
Muscle function (muscle strength, mass & power).
30 RCTs, 5615 participants; mean age 61.1 years (10-99 years); 72% female
Global muscle strength (29 RCTs): SMD 0.17 (95%CI 0.03, 0.31) (p=0.02)
Grip strength (16 RCTs): SMD 0.01 (95%CI -0.06, 0.07) (p=0.87)
Lower limb (16 RCTs): SMD 0.19 (95%CI 0.05, 0.34) (p=0.01)
Baseline 25(OH)D < 30 nmol/L: SMD 0.47 (95% CI, -0.07 to 1.01) (p=0.02)
Muscle mass (6 RCTs): SMD 0.058 (95%CI -0.118, 0.233) (p=0.520)
Muscle power (5 studies: SMD 0.057 (95%CI -0.194, 0.308) (p=0.657)
Small significant positive
effect of vitamin D on
muscle strength.
Improvement greater in
particpants with 25(OH)D <
30 nmol/L.
No significant effect on
muscle mass or muscle
power.
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