Connecting the dots between vitamin D deficiency and heart disease
Review provides additional rationale that supplementing vitamin D to correct deficiencies is a logical and important therapeutic strategy
Numerous studies to date have clearly demonstrated that there is a correlation between vitamin D deficiency and an increased risk of cardiovascular disease.
A 2015 review featured in BioMed Research International set out to evaluate those studies to determine the mechanism(s) that shed light on this association. As it turns out, there are several key pathways impacted when the body doesn’t have enough vitamin D.
Although the optimal level of vitamin D is still being debated among some healthcare professionals, this recent paper defines vitamin D deficiency as levels lower than 30ng/L. The authors cite inflammation as a key mechanism for the link between vitamin D deficiency and cardiovascular disease.
Adequate levels of vitamin D have been shown to suppress inflammation via several pathways. Vitamin D also inhibits vascular smooth muscle cellular proliferation, enhances endothelial function, promotes calcium homeostasis and protects against advanced glycation.
Vitamin D deficiency can also cause secondary hyperparathyroidism, which increases the risk of insulin resistance, thereby increasing risk of metabolic syndrome and diabetes, which are both linked to cardiovascular disease. Vitamin D deficiency is also linked to high cholesterol, hypertension and vascular stiffness — known risk factors for cardiovascular disease.
Although the research in this area is growing, results have been mixed. The researchers cite many reasons for these conflicting results including disparate dosing, short therapy dosing, individualised absorption and metabolism, study design flaws and biases, inappropriate follow-up or lack of a control, ethnicity, participant subjectivity and personal use of vitamin D.
They recommend future studies focus on bioavailability rather than simply total 25-hydroxyvitamin D. Seasonality should also be a consideration as levels may be lower during winter months. The researchers conclude by reminding healthcare professionals that screening for, and treating, vitamin D deficiency will likely help reduce cardiovascular morbidity and mortality.
This review elucidates why vitamin D deficiency can be dangerous to heart health. It also provides additional rationale that supplementing vitamin D to correct deficiencies is a logical and important therapeutic strategy.
