Vitamin D and Health

Compared with men in the top quartile of serum 25(OH)D concentration (≥ 70 nmol/L), men in the
lowest quartile (< 50 nmol/L) were at increased risk of hip fracture (HR=2.36; 95% CI, 1.08-5.15;
p trend=0.009). However, the association was attenuated by more than 50% (p trend=0.065) after
adjustment for BMD. Serum 25(OH)D concentration was unrelated to non-spine fractures.
6.116 Cauley et al. (2011) reported divergent associations between serum 25(OH)D concentration and risk of
fracture in a cohort of multi-ethnic women (white, n=400; black, n=381; Hispanic, n=193; Asian,
n=113; American Indian, n=46) followed over an average of 8.6 years. In multivariable models, serum
25(OH)D concentration > 50 nmol/L was associated with a lower risk of fracture in white women but a
higher fracture risk in black women. Serum 25(OH)D concentration > 75 nmol/L was associated with
higher fracture risk in Asian women; no significant associations were identified in the Hispanic or
Native American women.
6.117 A cohort study in Japan of community dwelling women (n=773; mean age, 74.6y) followed up for 6
years (Nakamura et al., 2011), reported that the adjusted hazard ratios of limb and vertebral fractures
for the first (< 48 nmol/L) and third quartile (59-71 nmol/L) of serum 25(OH)D concentration
compared to the fourth quartile (≥ 71.0 nmol/L) were 2.82 (95% CI, 1.09-7.34) and 2.82 (95% CI, 1.09-
7.27) respectively. However, the hazard ratio for the second quartile of serum 25(OH)D concentration
(≥ 47.7 to < 59.2 nmol/L) compared to the fourth quartile was not significant (HR=1.84; 95% CI, 0.68-
4.98). The pooled adjusted hazard ratio was 0.42 (95% CI, 0.18-0.99) when the incidence in the fourth
quartile (≥ 71.0 nmol/L) was compared to other three quartiles combined (< 71.0 nmol/L).
6.118 A cohort study in the USA, which followed community dwelling white and black participants (n=2614;
age, > 70y) for 6 years, found no evidence of an association between serum 25(OH)D concentration
and hip and non-vertebral fractures (Barbour et al., 2012).
6.119 A cohort study which followed healthy postmenopausal women in Saudi Arabia (n=912; mean age,
61y) for 5 years (Rouzi et al., 2012), reported that compared to being in the highest quartile of serum
25(OH)D concentration (45.1 nmol/L) being in the lowest quartile (≤ 17.9 nmol/L) was an independent
risk factor for osteoporosis related fractures (RR=1.63; 95% CI, 1.06-2.51).
Muscle strength and function
6.120 IOM Report: Although the IOM considered ‘physical performance’ and ‘falls’ as independent
indicators the evidence for both was considered together because of the integration of these
indicators in the literature reviewed. The IOM concluded that there was a lack of sufficiently strong
evidence (from RCTs and observational associations) on vitamin D with or without calcium and risk of
falls and poor physical performance to support DRI development. Evidence from RCTs in particular
showed outcomes that varied in significance and did not support observational findings or a causal
relationship. The IOM concluded that, overall, data from RCTs suggested that vitamin D doses of at
least 20 µg/d (800 IU), either alone or in combination with calcium, may have beneficial effects on
measures of physical performance; however, the evidence was considered insufficient to define the
shape of the dose-response curve for higher intakes.
Evidence considered since IOM report (Tables 25-27, Annnex 2)
Systematic reviews & meta-analyses
6.121 A systematic review and meta-analysis of 13 RCTs (n=2,268; mean age, 78y) assessed the efficacy of
vitamin D supplementation on muscle strength, gait and balance (Muir & Montero-Odasso, 2011). A
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