Vitamin D and Health

years) compared to the placebo group (IRR=1.15; 95% CI, 1.02-1.30 for fractures; IRR, 1.26; 95% CI,
1.00-1.59 for falls). Serum 25(OH)D concentration, which was measured in a subsample (n=137) of
participants, increased from a median of 49 nmol/L at baseline to 120 nmol/L after 1 month in the
vitamin D supplemented group and 90 nmol/L at 3 months, and remained higher than concentrations
in the placebo group 12 months after dosing. Data on serum levels of calcium were not reported.
7.21 Another RCT (Bischoff-Ferrari et al., 2016) of community-dwelling adults (n=200; age ≥70y with a prior
fall) randomised to receive a monthly dose of either 600 µg (24,000 IU) vitamin D 3 , 1500 µg
(60,000 IU) vitamin D 3 , or 600 µg (24,000 IU) vitamin D 3 + 300 µg 25(OH)D 3 for 12 months reported
that the incidence of falls was significantly higher in the 1500 µg (60,000 IU) vitamin D 3 group (66.9%;
95% CI, 54.4-77.5%) and the 600 µg (24,000 IU) vitamin D 3 + 300 µg 25(OH)D 3 group (66.1%; 95% CI,
53.5-76.8%) compared with the 600 µg (24,000 IU) vitamin D 3 group (47.9%; 95% CI, 35.8-60.3%)
(p=0.048).
7.22 Another study (Smith et al., 2007) reported a significant increase in non-vertebral fracture in women
(but not men) given an annual intra-muscular injection of vitamin D 2 (7500 μg/300,000 IU). No effect
was observed on the frequency of falls.
7.23 A cohort study in the USA (Cauley et al., 2011) reported that serum 25 (OH)D concentration
≥ 50 nmol/L was associated with lower fracture risk in white women but a higher fracture risk in black
women (OR=1.45, 95%CI 1.06-1.98) and that serum concentrations ≥ 75 nmol/L were associated with
a higher risk of fracture in Asian women.
Cancer
7.24 Pancreatic cancer: Some observational studies have reported an association between vitamin D
intakes/ serum 25(OH)D concentration and risk of pancreatic cancer, but the findings have not been
consistent. Skinner et al. (2006) reported that higher vitamin D intakes were significantly associated
with a reduced risk of pancreatic cancer while Stolzenberg-Solomon et al. (2006) reported a 3-fold
increase in pancreatic cancer risk in highest (65.5 nmol/L) vs lowest (< 32.0 nmol/L) quintile of serum
25(OH)D concentration (OR=2.92; 95% CI, 1.56-5.48, p trend = 0.001). A subsequent pooled study
using data from several cohorts (Stolzenberg-Solomon et al., 2010) reported that serum 25(OH)D
concentrations ≥ 100 nmol/L compared to 50 to < 75 nmol/L were associated with a statistically
significant increase in risk of pancreatic cancer (OR=2.12; 95% CI, 1.23-3.64). However, it has been
suggested that the positive association was a statistical artefact arising from the choice of cut-points
and that merging the top two groups largely abolished the relationship (Baggerly & Garland, 2012).
7.25 Prostate cancer: A nested case-control study (Tuohimaa et al., 2004), using stored serum from 3
cohorts of Nordic men (n=622 cases; n=1451 controls) reported that both low (≤ 19 nmol/L) and high
(≥ 80 nmol/L) serum 25(OH)D concentration was associated with higher risk of prostate cancer.
Another nested case-control study in Finland (Faupel-Badger et al., 2007) found no association
between serum 25(OH)D concentration in men who were smokers (n=296 cases, n=297 controls) and
risk of prostate cancer.
All-cause mortality
7.26 The IOM (2011) identified 6 cohort studies (Sambrook et al., 2004; Sambrook et al., 2006; Visser et al.,
2006; Jia et al., 2007; Melamed et al., 2008; Semba et al., 2009) that had examined the association
between serum 25(OH)D concentration and all-cause mortality. Overall, these studies reported that
concentrations < 30 nmol/L were associated with an increased mortality risk, which decreased as
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