The effects of vitamin D, K and calcium co-supplementation on carotid intima-media thickness and metabolic status in overweight type 2 diabetic patients with CHD.

The British journal of nutrition

May 2016

DOI: 10.1017/S0007114516001847

Citations:48

Influential Citations:4

Interventional (Human) Studies

Enhanced Details

Methods

Randomised, double-blind, placebo-controlled trial with intention-to-treat analysis; overweight adults with type 2 diabetes mellitus and coronary heart disease (BMI ≥25 kg/m2; age 40–85); 66 participants (33 per group) randomized to receive the combination supplement or placebo for 12 weeks.

Intervention

Combination tablet containing vitamin D 5 µg, vitamin K2 (MK-7) 90 µg, and calcium 500 mg; taken twice daily for 12 weeks.

Results

Maximum left CIMT decreased by 0.04 mm in the intervention group versus a 0.04 mm increase in the placebo group (P = 0.02). No significant effects on mean left CIMT, mean right CIMT, or maximum right CIMT. Metabolic improvements with supplementation included: serum 25(OH)D up by 6.5 ng/mL vs 0.4 ng/mL (P < 0.001); calcium up by 0.6 mg/dL vs 0.1 mg/dL (P < 0.001); insulin −0.9 vs +2.6 µIU/mL (P = 0.01); HOMA-IR −0.4 vs +0.7 (P = 0.01); HOMA-B −2.1 vs +8.9 (P = 0.01); QUICKI +0.007 vs −0.006 (P = 0.01); HDL-cholesterol +2.7 mg/dL vs −2.5 (P = 0.002); hs-CRP −1320.1 ng/mL vs +464.0 (P = 0.03); MDA −0.4 vs −1.0 µmol/L (P = 0.007). No significant changes in other lipids or oxidative stress markers. The combination may improve left CIMT and metabolic status in overweight T2DM with CHD, though the left CIMT finding could be a chance finding.

Limitations

Small sample size (n=66); short duration (12 weeks); did not assess vitamin K status, osteocalcin or MGP, or other inflammatory markers; did not measure vascular elasticity/dispensability; potential confounding from combining multiple nutrients rather than isolating effects; study population limited to elderly, overweight individuals with CHD; seasonal factors (summer study period) may affect vitamin D status; baseline CIMT levels were near-normal, potentially limiting detectable changes.

Abstract

This study was conducted to examine the effects of vitamin D, K and Ca co-supplementation on carotid intima-media thickness (CIMT) and metabolic status in overweight diabetic patients with CHD. This randomised, double-blind, placebo-controlled trial was conducted among sixty-six diabetic patients with CHD. Participants were randomly allocated into two groups to take either 5µg vitamin D, 90 µg vitamin K plus 500 mg Ca supplements (n 33) or placebo (n 33) twice a day for 12 weeks. Fasting blood samples were obtained at the beginning of the study and after the 12-week intervention period to determine related markers. Vitamin D, K and Ca co-supplementation resulted in a significant reduction in maximum levels of left CIMT (-0·04 (sd 0·22) v. +0·04 (sd 0·09) mm, P=0·02). Changes in serum vitamin D (+6·5 (sd 7·8) v. +0·4 (sd 2·2) ng/ml, P<0·001), Ca (+0·6 (sd 0·3) v. +0·1 (sd 0·1) mg/dl, P<0·001) and insulin concentrations (-0·9 (sd 3·1) v. +2·6 (sd 7·2) µIU/ml, P=0·01), homoeostasis model for assessment of estimated insulin resistance (-0·4 (sd 1·2) v. +0·7 (sd 2·3), P=0·01), β-cell function (-2·1 (sd 9·0) v. +8·9 (sd 23·7), P=0·01) and quantitative insulin sensitivity check index (+0·007 (sd 0·01) v. -0·006 (sd 0·02), P=0·01) in supplemented patients were significantly different from those in patients in the placebo group. Supplementation resulted in significant changes in HDL-cholesterol (+2·7 (sd 7·0) v. -2·5 (sd 5·7) mg/dl, P=0·002), high-sensitivity C-reactive protein (-1320·1 (sd 3758·3) v. +464·0 (sd 3053·3) ng/ml, P=0·03) and plasma malondialdehyde concentrations (-0·4 (sd 0·5) v. -1·0 (sd 1·1) µmol/l, P=0·007) compared with placebo. Overall, vitamin D, K and Ca co-supplementation for 12 weeks among diabetic patients with CHD had beneficial effects on maximum levels of left CIMT and metabolic status. The effect of vitamin D, K and Ca co-supplementation on maximum levels of left CIMT could be a chance finding. show less