Objective: The aim of this study was to identify the potential relationships between plasma 25-hydroxyvitamin D3 (25OHD3), C-reactive protein (CRP), coronary artery atherosclerosis (CAA), and coronary artery remodeling in monkeys consuming atherogenic diets.
Methods: Female cynomolgus monkeys (n = 74) were fed a casein-lactalbumin (C/L)–based, moderately atherogenic diet for 12 months. They then consumed either a soy-based (n = 35) or C/L-based (n = 39) diet for 32 months. CRP concentrations were then determined, and monkeys underwent surgical menopause. Each diet group was then rerandomized to receive soy (n = 36) or C/L (n = 38). After 32 postmenopausal months, 25OHD3, CRP, CAA, and coronary artery remodeling were determined. All monkeys received a woman’s equivalent of 1,000 IU/day of vitamin D3 and 1,200 mg/day of calcium throughout the study.
Results: The premenopausal and postmenopausal dietary protein sources had no effect on postmenopausal 25OHD3 concentrations (P = 0.6). Across treatment groups, there was a statistically significant inverse relationship between 25OHD3 concentrations and CRP at necropsy (r = −0.35, P = 0.003). A significant inverse correlation between 25OHD3 concentration and the change in CRP from premenopause to postmenopause was observed (r = −0.32, P = 0.007). The significant associations identified between plasma 25OHD3 and CRP remained after controlling for postmenopausal diet. Those monkeys with a greater increase in CRP also had significantly more CAA and less ability to maintain normal lumens by remodeling.
Conclusions: Higher plasma concentrations of 25OHD3 were associated with lower CRP. Lower CRP was associated with less coronary atherosclerosis and improved coronary artery remodeling. These findings suggest that 25OHD3 concentrations are associated with an anti-inflammatory state and may support an association between oral vitamin D3 and cardioprotection.