Calcium Plus Vitamin D Supplementation and the Risk of Incident Diabetes in the Women's Health Initiative

Boer, Ian H. de; Tinker, Lesley F.; Connelly, Stephanie; Curb, J. David; Howard, Barbara V.; Kestenbaum, Bryan; Larson, Joseph C.; Manson, JoAnn E.; Margolis, Karen L.; Siscovick, David S.; Weiss, Noel S.

doi:10.2337/dc07-1829

Cited by 333 publications

(288 citation statements)

References 34 publications

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“…Our findings are in line with the Women's Health Initiative trial that found no effect of combined supplementation with 1000 mg of calcium and 400 IU of vitamin D on incident type 2 diabetes over 7-year follow-up (RR 1.01, 95% CI 0.94 --1.10). 9 The null result of this trial indicates associations of calcium supplementation with reduced diabetes risk observed in nonrandomized studies 3,10 may be the result of confounding. Also, most intervention studies examining the effects of calcium supplementation (alone or as a component of dairy products) on blood glucose or insulin resistance reported no evidence of effects.…”

Section: Discussionmentioning

confidence: 99%

Dietary calcium intake and risk of type 2 diabetes: possible confounding by magnesium

2012

Eur J Clin Nutr

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This study examined the association of dietary calcium intake with incident type 2 diabetes by a meta-analysis and explored the potential confounding by magnesium. Potential studies were identified by searching the PubMed database in September 2011. Prospective cohort studies that reported relative risks (RR) with 95% confidence intervals (CI) of type 2 diabetes for dietary calcium intake were selected. Results were combined using either a fixed-or random-effects model. Six prospective cohort studies comprising 264 268 participants and 11 225 reported cases were included. All combined random-effects metaanalysis yielded a significant pooled RR of 0.85 (95% CI 0.75 --0.97). However, a sensitivity analysis limited to four studies with control for magnesium yielded an attenuated, nonsignificant pooled RR of 0.94 (95% CI 0.85 --1.05). In conclusion, dietary calcium intake was not independently associated with risk of type 2 diabetes. The inverse association in prior observational studies may be partially confounded by magnesium intake.

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Section: Discussionmentioning

confidence: 99%

Dietary calcium intake and risk of type 2 diabetes: possible confounding by magnesium

2012

Eur J Clin Nutr

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“…Several studies have demonstrated that vitamin D can improve insulin resistance in patients with prediabetic states including insulin resistance and impaired glucose tolerance [10,11,25,26]. However, studies examining the effect of vitamin D on insulin resistance and glycaemic control in patients with established type 2 diabetes have been negative [9,10], and the large Women's Health Initiative study [27] found no reduction in new diagnoses of diabetes in participants receiving calcium plus a small (400 IU per day) dose of vitamin D 3 . Similarly, a post hoc analysis of the large MRC RECORD trial of calcium and vitamin D supplementation showed no reduction in self-reported newonset diabetes or new-onset use of insulin or hypoglycaemic medication, despite the vitamin D dose in this trial being 800 IU per day [28].…”

Section: Discussionmentioning

confidence: 99%

The effect of different doses of vitamin D3 on markers of vascular health in patients with type 2 diabetes: a randomised controlled trial

et al. 2010

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Aims/hypothesis Low 25-hydroxyvitamin D levels predict future cardiovascular events and are common in patients with type 2 diabetes. We compared the effect of 100,000 and 200,000 IU doses of vitamin D 3 on endothelial function, blood pressure and markers of glycaemic control in patients with type 2 diabetes. Methods This was a randomised, parallel group, placebocontrolled trial. Patients with type 2 diabetes and baseline 25-hydroxyvitamin D levels <100 nmol/l were enrolled from community and hospital-based diabetes clinics. Participants were assessed in a university department of clinical pharmacology and received a single oral dose of placebo or vitamin D 3 (100,000 IU or 200,000 IU) at baseline, randomly allocated via numbered bottles prepared offsite; participants and investigators were both blinded to treatment allocation. Endothelial function, office blood pressure, B-type natriuretic peptide, insulin resistance and glycosylated haemoglobin were measured at baseline, and at 8 and 16 weeks.

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“…28 -47 kg/m 2 ) subjects on glucose metabolism after 1 year (89) . Similarly, using data from the Women's Health Initiative, de Boer et al (90) showed that the incidence of diabetes at age 7 years did not differ between those receiving Ca and vitamin D compared with those receiving the placebo and there was no difference in fasting plasma glucose, insulin or HOMA-IR. Thus, the association between s25(OH)D concentrations and altered glucose and insulin metabolism reported Vitamin D and cardiometabolic healthwidely in cross-sectional and prospective studies requires confirmation by RCT using vitamin D only.…”

Section: Glucose and Insulin Metabolism And Type 2 Diabetesmentioning

confidence: 99%

Vitamin D and cardiometabolic health: a review of the evidence

Muldowney

Kiely

2010

Nutr. Res. Rev.

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The cardiometabolic syndrome (MetS) is a clustering of related metabolic abnormalities including abdominal adiposity, insulin resistance, hypertension, dyslipidaemia and increased inflammatory and thrombotic markers, which is linked to increased risk of type 2 diabetes, CVD and overall mortality. Several cross-sectional and prospective studies have shown an association between low vitamin D status, as indicated by concentrations of serum 25-hydroxyvitamin D (s25(OH)D), and increased prevalence of the MetS and individual CVD risk factors. These epidemiological observations are supported by mechanistic studies but experimental data are limited. The available data from intervention studies are largely confounded as most vitamin D supplementation trials were mainly carried out to explore the role of Ca in CVD and include Ca in the treatment arms. Inadequate consideration of seasonal effects on s25(OH)D concentrations is also a common design flaw in most studies. Further complications arise from shared risk factors such as adiposity and ageing, which predispose individuals to exhibit both a more pronounced risk profile and relatively lower s25(OH)D concentrations. In conclusion, while epidemiological associations are promising and a rationale for low vitamin D status as a potentially modifiable risk factor for CVD is supported by mechanistic data, suitable experimental data from appropriately designed trials are just beginning to emerge. As yet, this body of literature is too immature to draw firm conclusions on the role of vitamin D in CVD prevention. Carefully controlled vitamin D trials in well-described population groups using intervention doses that are titrated against target s25(OH)D concentrations could yield potentially valuable outcomes that may have a positive impact on CVD risk modification.

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Calcium Plus Vitamin D Supplementation and the Risk of Incident Diabetes in the Women's Health Initiative

Cited by 333 publications

References 34 publications

Dietary calcium intake and risk of type 2 diabetes: possible confounding by magnesium

Dietary calcium intake and risk of type 2 diabetes: possible confounding by magnesium

The effect of different doses of vitamin D3 on markers of vascular health in patients with type 2 diabetes: a randomised controlled trial

Vitamin D and cardiometabolic health: a review of the evidence

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