High-dosed vitamin D supplements lower the risk of heart attacks

- in people aged 60 and older

Cardiovascular disease is the leading cause of death worldwide, and our diet and lifestyle play a major role. According to an Australian study published in British Medical Journal, high-dosed vitamin D supplementation taken for several years lowers the risk of heart attacks or interventions such as angioplasty and by-pass surgery in people aged 60 years and older.

Several observational studies have shown a link between vitamin D deficiency and the risk of developing cardiovascular disease. Some randomized, controlled studies have failed to show a protective effect of vitamin D, however, but this is most likely because the doses have been too small to optimize blood levels of the nutrient and to influence other relevant parameters.
Therefore, a team of Australian scientists wanted to carry out a study to see if vitamin D taken in substantially higher doses that the recommended amount could lower the risk of cardiovascular disease, including heart attack and stroke.
Their study (D-Health Trial) was conducted in the period between 2014 and 2020 and involved 21,315 Australians in the ages 60-84 years. The participants were divided into two groups. For a period of five years, one group got a capsule with 1,500 mcg (=60,000 IU) of vitamin D once per month, which is the equivalent of around 50 micrograms per day. This is substantially more than the official recommendations for adults over 70 years (5-20 micrograms). The other group got matching placebo.
Participants with elevated calcium levels in their blood (hypercalcemia), overactive adrenal glands (hyperparathyroidism), kidney stones, soft bones (osteomalacia), and sarcoidosis were excluded from the trial. This was also the case with participants who already took vitamin D supplements containing more than 12.5 micrograms (500 IU) of vitamin D.
The participants were asked to fill in questionnaires with information about their health status, lifestyle, and eating habits.
During the course of the study, blood levels of vitamin D as 25(OH)D) were measured and were registered as 77 nmol/L on average in the placebo group and 115 nmol/L in the vitamin D group.
The scientists also collected patient data from hospitals concerning death and serious cardiovascular disease that involved heart attacks, stroke, and interventions such as angioplasty (PCI) or by-pass (CABG)
It turned out that 1,336 participants had experienced serious cardiovascular events with 6.6 percent in the placebo group and 6 percent in the vitamin D group. In other words, there were 9 percent fewer serious cardiovascular events in the vitamin D group. More specifically, compared to the placebo group, the following was observed in the vitamin D group:

• 19 percent fewer heart attacks
• 11 percent fewer cases of by-pass surgery and angioplasty
• No difference was registered between the groups with regard to stroke

Apparently, high-dosed vitamin D supplementation that effectively optimizes blood levels of vitamin D and raises them way over what is considered a sufficient level (75 nmol/L) can lower the risk of cardiovascular disease. This is particularly true for heart attacks and different surgical interventions like angioplasty and bypass surgery.

How does vitamin D prevent a heart attack?

According to a review article that is published in Clinical Nutrition, vitamin D has the following protective mechanisms:

• It regulates blood pressure by affecting endothelial cells and soft vascular muscle cells
• It counteracts stiff arteries and enlargement of the left ventricle
• It controls inflammation that can cause oxidative stress and atherosclerosis
• It controls blood sugar levels and insulin levels
• It contributes to the prevention of metabolic syndrome and type 2 diabetes that are associated with circulatory disorders and elevated cholesterol levels

References:

Thompson B et al. Vitamin D supplementation and major cardiovascular events: D-Health randomised controlled trial. BMJ 2023

Megan Craig. Vitamin D may reduce the risk of heart attacks in people over 60. Medical News Today. 2023

Fernando de la Guia-Galipienso et al. Vitamin D and cardiovascular health. Clinical Nutrition. 2021

Anbefalinger om D-vitamin - Sundhedsstyrelsen