Vitamin D and Health

(Gallicchio et al., 2010; Mondul et al., 2014) or non-Hodgkin lymphoma (Purdue et al., 2010). Out of 2
studies on liver cancer (Wang et al., 2013a; Fedirko et al., 2014), 1 (Fedirko et al., 2014) reported that
serum 25(OH)D concentration < 50 nmol/L vs ≥ 75 nmol/L was associated with a 49% reduced risk of
liver cancer (IRR=0.51; 95% CI, 0.26-0.99). Out of 2 studies on bladder cancer (Mondul et al., 2010;
Mondul et al., 2012), 1 (Mondul et al., 2010) reported that serum 25(OH)D concentration < 25 nmol/L
vs ≥ 50 nmol/L was associated with a significantly increased risk of bladder cancer (OR=1.73; 95% CI,
1.03-2.91). Three studies on melanoma reported a non-significantly higher risk in people with serum
25(OH)D concentration ≥ 50 nmol/L compared to < 25 nmol/L (Major et al., 2012; Afzal et al., 2013)
and ≥ 75 compared to < 75 nmol/L (van der Pols et al., 2013). A meta-analysis (Caini et al., 2014)
reported that higher serum 25(OH)D concentration was associated with a significant increase in risk in
basal cell skin cancer (4 studies 66 ; RR=1.82; 95% CI, 1.38-2.40) and non-melanoma skin cancer (2
studies 67 ; RR=1.64; 95% CI, 1.02-2.65). Stolzenberg-Solomon et al. (2010) reported a significant
increase in pancreatic cancer risk associated with higher (≥ 100 nmol/L) compared to lower
(< 25 nmol/L) serum 25(OH)D concentration.
Summary - Cancers
6.213 The small number of RCTs have not shown an effect of vitamin D supplements on overall cancer risk.
6.214 Observational studies indicate an inverse association between serum 25(OH)D concentration and colorectal
cancer risk. This might be due to a protective effect, reverse causality, or residual confounding by other factors
such as obesity, physical activity and smoking.
6.215 There is no strong evidence of associations between serum 25(OH)D concentration and risk of cancer at other
sites. Although studies of skin cancer suggest risk may be increased in individuals with a relatively high serum
25(OH)D concentration this might be because a high serum 25(OH)D concentration is a marker of high sun
exposure.
Cardiovascular disease & hypertension
6.216 Cardiovascular disease (CVD) encompasses a range of diseases of the heart and circulation including
coronary heart disease, angina, heart attack, congenital heart disease and stroke. There are several
risk factors for CVD, including: smoking, high blood pressure, high blood cholesterol, physical
inactivity, overweight, diabetes, family history, sex and age 68 .
6.217 CVD is predominantly caused by atherosclerotic deposits in large and medium size arteries. These
deposits are characterised by lipid deposition and inflammation. In addition, calcification is a
significant component of advance atherosclerotic lesions. It is important, therefore, to also consider
the impact of calcium intake in relation to atherosclerotic CVD. The decline in CVD mortality over the
last 20 years has been mainly due to better medical treatment for CVD and its associated risk factors.
6.218 Several lines of evidence have been suggested in support of a biologically plausible relationship
between serum 25(OH)D concentration and cardiovascular events. Animal studies have shown that
VDR knockout mice develop heart failure despite normalised calcium concentrations (Bouillon et al.,
2008). Animal studies have also suggested a link between ingested vitamin D and atherosclerosis
(Toda et al., 1983; Toda et al., 1985). It has been proposed (R Fraser, personal communication, 2011)
66 Serum 25(OH)D concentrations (nmol/L) in top vs bottom quantile in the 4 studies were: >85 vs < 51; >78 vs 37.4 vs 75 vs 50 vs 75 vs