Do vitamin D and calcium supplements accelerate atherosclerosis (hardening of the arteries)?

From the Guidelines

Vitamin D and calcium supplementation, when taken in recommended doses, does not accelerate atherosclerosis in generally healthy adults. The relationship between vitamin D, calcium, and atherosclerosis is complex and not fully established. Current evidence, as seen in the study by the National Osteoporosis Foundation and the American Society for Preventive Cardiology 1, does not conclusively show that normal supplementation of vitamin D and calcium accelerates atherosclerosis in most people. However, excessive calcium supplementation (typically above 1,000-1,200 mg daily) may potentially contribute to vascular calcification in certain individuals, particularly those with existing cardiovascular disease or kidney problems. For vitamin D, maintaining normal levels (generally 30-50 ng/mL) appears beneficial for cardiovascular health rather than harmful, as suggested by the study on steroid hormone vitamin D implications for cardiovascular disease 1.

Key Considerations

• The body carefully regulates calcium metabolism, and problems typically arise when this regulation is disrupted by excessive supplementation or underlying health conditions.
• For most healthy adults, following recommended daily allowances (600-800 IU of vitamin D and 1,000-1,200 mg of calcium for adults) is unlikely to promote atherosclerosis.
• These nutrients are essential for bone health and numerous bodily functions, and deficiencies can lead to other health problems.
• If you have cardiovascular concerns, it's advisable to discuss appropriate supplementation with your healthcare provider, who may recommend blood tests to check your current levels before supplementing.

Evidence Summary

The study by the National Osteoporosis Foundation and the American Society for Preventive Cardiology 1 provides moderate-quality evidence that calcium with or without vitamin D intake from food or supplements has no relationship to the risk for cardiovascular and cerebrovascular disease, mortality, or all-cause mortality in generally healthy adults. This guideline suggests that calcium intake from food and supplements that does not exceed the tolerable upper level of intake should be considered safe from a cardiovascular standpoint. In contrast, the study on steroid hormone vitamin D implications for cardiovascular disease 1 highlights the potential effects of vitamin D-hormones on the vasculature, including the possibility of acceleration of both atherosclerosis and cardiovascular calcification. However, this study also notes that the effects of vitamin D-hormones are double-edged, with potential benefits to bone density at the cost of cardiovascular morbidity and mortality due to calcific vasculopathy and valvulopathy.

Clinical Implications

Given the complexity of the relationship between vitamin D, calcium, and atherosclerosis, it is essential to prioritize individualized assessment and monitoring. Healthcare providers should consider a patient's overall health status, cardiovascular risk factors, and current supplementation levels when making recommendations about vitamin D and calcium intake. Additionally, regular monitoring of cardiovascular health and bone density can help identify potential issues early on, allowing for timely interventions to mitigate risks and optimize benefits.

From the Research

Vitamin D and Calcium's Effect on Atherosclerosis

• The relationship between vitamin D, calcium, and atherosclerotic risk is complex, with evidence suggesting that vitamin D may be related to lower risk of cardiovascular disease (CVD) 2.
• Vitamin D has been shown to exert protective effects on atherosclerosis through multiple mechanisms, including protecting against endothelial dysfunction and vascular smooth muscle cell proliferation and migration 3.
• Calcium supplementation, on the other hand, may elevate CVD risk, although dietary intake of calcium may be associated with lower CVD risk 2.
• Vitamin D deficiency has been linked to cardiovascular disease and atherosclerosis, with observational studies reporting an association between vitamin D deficiency and risk of hypertension, atherosclerosis, and heart failure 4.

Acceleration of Atherosclerosis

• There is no strong evidence to suggest that vitamin D and calcium accelerate atherosclerosis, with some studies suggesting that vitamin D may have protective effects on atherosclerosis 3, 4.
• However, the relationship between vitamin D and CVD risk is puzzling, with observational data indicating an inverse nonlinear association between vitamin D status and CVD events, but randomized controlled trials showing no significant beneficial effect of vitamin D treatment on CVD events 5.
• The role of vitamin D in the cardiovascular system is complex, with local vitamin D levels influencing relevant systemic consequences independently of its circulating pool, and vitamin D linking closely to other signalling pathways of CV relevance 6.

Calcium's Role

• The picture for calcium is more complex, with dietary intake of calcium potentially being associated with lower CVD risk, while calcium supplementation may elevate CVD risk 2.
• The mechanisms by which calcium supplementation may increase CVD risk are not fully understood, but may be related to the effects of calcium on vascular smooth muscle cell proliferation and migration 2.