The effects of calcium and vitamin D supplementation on blood glucose and markers of inflammation in nondiabetic adults

Pittas et al., 2007 | Diabetes Care | Rct

Citation

Pittas Anastassios G, Harris Susan S, ... Dawson-Hughes Bess. The effects of calcium and vitamin D supplementation on blood glucose and markers of inflammation in nondiabetic adults. Diabetes Care. 2007-Apr;30(4):980-6

Abstract

OBJECTIVE: We sought to compare the effects of combined calcium and vitamin D supplementation versus placebo on blood glucose and markers of inflammation in nondiabetic adults aged > or =65 years. RESEARCH DESIGN AND METHODS: A total of 314 Caucasian adults without diabetes received either 500 mg calcium citrate and 700 IU vitamin D(3) or placebos daily for 3 years in a double-blind, randomized, controlled trial designed for bone-related outcomes. In a post hoc analysis, fasting plasma glucose (FPG), insulin sensitivity (estimated by homeostasis model assessment of insulin resistance [HOMA-IR]), plasma C-reactive protein, and interleukin-6, were measured at baseline and 3 years. RESULTS: The effects of combined calcium-vitamin D supplementation on 3-year change in FPG depended on baseline FPG (P = 0.02 for interaction). Therefore, we conducted analyses separately in participants with normal fasting glucose (NFG) (FPG <5.6 mmol/l, n = 222) and impaired fasting glucose (IFG) (FPG 5.6-6.9 mmol/l, n = 92) at baseline. Among participants with IFG at baseline, those who took combined calcium-vitamin D supplements had a lower rise in FPG at 3 years compared with those on placebo (0.02 mmol/l [0.4 mg/dl] vs. 0.34 mmol/l [6.1 mg/dl], respectively, P = 0.042) and a lower increase in HOMA-IR (0.05 vs. 0.91, P = 0.031). In the NFG subgroup, there was no difference in the change in FPG or HOMA-IR between the two treatment arms. There were no differences in C-reactive protein or interleukin-6 between the two treatment arms in either subgroup. CONCLUSIONS: In healthy, older adults with IFG, supplementation with calcium and vitamin D may attenuate increases in glycemia and insulin resistance that occur over time. However, our findings should be considered hypothesis generating and need to be confirmed in randomized trials specifically designed for the outcomes of interest.

Key Findings

The effects of combined calcium-vitamin D supplementation on 3-year change in FPG depended on baseline FPG (P = 0.02 for interaction). Therefore, we conducted analyses separately in participants with normal fasting glucose (NFG) (FPG <5.6 mmol/l, n = 222) and impaired fasting glucose (IFG) (FPG 5.6-6.9 mmol/l, n = 92) at baseline. Among participants with IFG at baseline, those who took combined calcium-vitamin D supplements had a lower rise in FPG at 3 years compared with those on placebo (0.02

Outcomes Measured

• Requires manual extraction

Population

MeSH Terms

• Aged
• Biomarkers
• Blood Glucose
• Body Mass Index
• Body Weight
• Calcium, Dietary
• Dietary Supplements
• Female
• Humans
• Hyperglycemia
• Inflammation
• Insulin
• Male
• Reference Values
• Vitamin D

Evidence Classification

• Level: Rct
• Publication Types: Journal Article, Randomized Controlled Trial, Research Support, N.I.H., Extramural, Research Support, U.S. Gov't, Non-P.H.S.
• Vertical: vitamin-d-diabetes

Provenance

• PMID: 17277040
• DOI: (not available)
• PMCID: Not in PMC
• Verified: 2026-04-09 via PubMed E-utilities API

Source extracted via PubMed E-utilities API on 2026-04-09