How to Prevent Heart Attack and Stroke with Vitamin D?

How to Prevent Heart Attack and Stroke with Vitamin D?

High monthly doses of vitamin D would not prevent cardiovascular disease.

Why it’s important

Epidemiological studies indicate that the risk of cardiovascular disease is higher when there is a lack of vitamin D. But these are observational studies, not allowing to draw a conclusion of cause and effect. Vitamin D is naturally made by the body when exposed to ultraviolet radiation from the sun. Vitamin D can also be found in foods such as oily fish, eggs and vitamin D fortified milk. The risk of cardiovascular disease is higher in people with low vitamin D levels; cardiovascular diseases are more common in winter when the body has little vitamin D. Knowing this, what happens when you take supplements to protect yourself from deficits?

This is what an intervention study published in 2017 intended to evaluate. Its results show that there is no miraculous martingale, and that the biology of vitamin D is much more complex than previously thought.

The studies

New Zealand researchers followed the heart health of 5,100 adults aged 50 to 84 between April 2011 and November 2012, some of whom took high doses of vitamin D every month. The study appeared in JAMA Cardiology. Follow-up lasted until July 2015, more than three years. The average age of participants was 65.9 years and 58% were men. The mean concentration of vitamin D in the participants’ blood was 26.5 ng / mL at baseline and about a quarter (1270) had vitamin D deficiency at baseline, with less than 50 nmol / L of vitamin D in the blood. Half of the group (2558 people) had a high dose of vitamin D once a month, with an initial dose of 200,000 IU, then a monthly dose of 100,000 IU. The other half of the group (2552 people) took a placebo.

At the end of the trial, about 12% of people in both groups developed cardiovascular disease: 11.8% in the vitamin D group and 11.5% in the placebo group. Similar results were observed for participants who initially had vitamin D deficiency. The risk of developing high blood pressure, having a heart attack, stroke, heart failure or angina pectoris was the same, with or without vitamin D.

In a study published in January 2018 in International Journal of Nanomedicine, researchers have shown instead that vitamin D3 could help to treat or prevent cardiovascular damage caused by diseases. Tadeusz Malinski, one of the authors of this research, said in a statement from Ohio University “In recent years, in clinical settings, people recognize that many patients who have a heart attack have a disability of vitamin D3. This does not mean that the deficiency caused the heart attack, but it increased the risk of heart attack. 

His team used nanosensors to determine the impact of vitamin D3 on blood vessel cells. The researchers worked on a cellular model of hypertension. They found that vitamin D3 stimulates nitric oxide (NO), a signal molecule that promotes vasodilation and prevents the formation of blood clots. Vitamin D3 also reduces oxidative stress in the cardiovascular system.

Based on these results, the authors suggest that vitamin D3 could restore damage to the cardiovascular system caused by various diseases (hypertension, diabetes, atherosclerosis, stroke…) and reduce the risk of heart attack. “It’s a very inexpensive solution to repair the cardiovascular system. We do not need to develop a new drug. We already have it. 

In practice

While epidemiological studies suggest that good vitamin D status protects against cardiovascular disease, clinical trials are needed to verify it. The WHI study did not find any benefit from a daily supplement of vitamin D (with calcium), but this result was criticized because the dose of vitamin D was low (400 IU / d). Another intervention study reported a 10% reduction in the incidence of cardiovascular disease after 4 months of supplementation (monthly dose of 100,000 IU). But the decrease was not significant. Another study aimed at reducing fractures showed (in the second analysis) that taking vitamin D (800 IU / day) reduced the risk of heart failure by 25%, but not heart attacks and strokes. The latest New Zealand study shows that a high monthly dose does not reduce cardiovascular disease. It remains to be seen what would happen with a daily dose greater than 800 IU, or a weekly dose. The problem with high monthly doses is that vitamin D remains only a few days in circulation due to its short half-life. Another hypothesis: the vitamin D level is only a marker of sun exposure, which would have other benefits than the only impact on the vitamin D level.

The authors of the study do not therefore consider that the file is closed. In the meantime, it is probably best, if you are in a deficit, to take daily or weekly supplements, rather than monthly supplements . We advise to have a circulating vitamin D between 30 to 45 ng / mL.