Vitamin D and Triglycerides: Evidence of a Clear Association
Yes, there is a well-established inverse relationship between vitamin D levels and triglycerides—lower vitamin D levels are consistently associated with higher triglyceride levels, and vitamin D supplementation can reduce triglycerides in deficient individuals. 1, 2
The Evidence for the Link
Observational Data Demonstrates Strong Correlation
The relationship between vitamin D deficiency and elevated triglycerides has been documented across multiple large-scale studies:
In a cohort of 3,788 subjects in northern China, serum 25(OH)D showed a significant inverse correlation with triglycerides (β coefficient = -0.077, p < .05), meaning lower vitamin D levels predicted higher triglyceride levels. 3
A population-based study of 909 men aged 45-70 years found that 25-hydroxyvitamin D had a significant inverse association with triglycerides (β = -0.17, P < 0.001), and this relationship persisted even after adjusting for age, waist circumference, BMI, alcohol consumption, smoking, renal function, glucose tolerance, and insulin sensitivity. 4
Cross-sectional data from 130 participants demonstrated significant differences in triglyceride levels according to vitamin D status, with vitamin D deficiency having a negative impact on triglyceride levels. 5
Interventional Evidence Shows Causality
The most compelling evidence comes from randomized controlled trials showing that vitamin D supplementation actually reduces triglycerides:
An RCT in 200 healthy overweight individuals showed that 12 months of vitamin D supplementation (83 μg/day, approximately 3,320 IU/day) resulted in a significant reduction of triglycerides compared to placebo (though LDL-cholesterol increased in the supplementation group). 1, 2
A 2019 meta-analysis of 41 RCTs comprising 3,434 participants found that vitamin D supplementation reduced triglycerides with a standardized mean difference of -0.15 (95% CI: -0.24 to -0.06). 6
The improvements in triglycerides were more pronounced in participants with baseline vitamin D deficiency, suggesting that correcting deficiency is key to seeing lipid benefits. 6
Mechanistic Plausibility
The biological mechanisms linking vitamin D to triglyceride metabolism include:
- Vitamin D improves insulin secretion and insulin sensitivity, which directly affects triglyceride metabolism. 1, 2
- Vitamin D reduces inflammation and TNF-alpha levels, which are implicated in dyslipidemia. 1, 2
- The presence of vitamin D receptors in multiple tissues suggests direct metabolic effects on lipid handling. 1
Clinical Implications
For patients with elevated triglycerides and suspected vitamin D deficiency, check 25(OH)D levels and treat deficiency according to standard protocols:
- If vitamin D deficiency is documented (≤15 ng/mL), treat with ergocalciferol 50,000 IU weekly for 8-12 weeks, followed by maintenance therapy of 800-1,000 IU daily. 2
- Monitor serum calcium and phosphorus every 3 months during treatment. 2
- Target 25(OH)D levels of at least 30-40 ng/mL for optimal health benefits beyond bone health. 1, 7
Important Caveat: Laboratory Interference
Be aware that very high triglyceride levels (>10.17 mmol/L or approximately >900 mg/dL) can cause falsely low vitamin D measurements due to laboratory interference. 8
- In patients with triglycerides above 10.17 mmol/L, the mean measured 25(OH)D level was only 12.28 mg/L compared to 20.11 mg/L in those with normal triglycerides. 8
- No patients with triglycerides >10.17 mmol/L had vitamin D levels above 100 mg/L, suggesting systematic underestimation. 8
- Exercise caution when interpreting vitamin D levels in patients with severe hypertriglyceridemia, as the deficiency may be artifactual and inappropriate supplementation could risk toxicity. 8