Cardiologist: “Too much vitamin D harms heart health”.
Although this is repeatedly claimed, there is no high-quality scientific evidence that vitamin D can lower blood pressure. A renowned American institution now warns against taking vitamin D for high blood pressure. Too much vitamin D could even endanger heart health, it says.
Dr. Steven Nissen is a cardiologist at the Cleveland Clinic (USA). In a recent post from the clinic, the heart expert explains the links between vitamin D and heart health. “There are many claims about the benefits of vitamin D for heart health, but they are not supported by high-quality scientific studies,” Dr. Nissen points out.
Vitamin D does not protect against cardiovascular events
For example, a 2019 study of 25,871 participants published in the New England Journal of Medicine concluded that vitamin D intake did not result in a lower incidence of cardiovascular events compared with a placebo.
Consequences for the heart of too much vitamin D
According to Dr. Nissen, while vitamin D plays an important role in regulating blood pressure, it is a complicated process. Excessive intake could even lead to excess calcium or hypercalcemia, which is a disturbance in calcium and phosphate balance, he said. “Vitamin D enables the absorption of calcium,” the cardiologist explains. Theoretically, too high a level could cause calcium deposits to form on the walls of blood vessels, in heart valves and even in the liver and kidneys. For this reason, vitamin D is not suitable for lowering blood pressure.
When it makes sense to take vitamin D
Vitamin D is an essential vitamin overall, he said. The body synthesizes vitamin D primarily through exposure to natural sunlight. Most foods do not contain significant amounts of the nutrient. So it may make sense to take some vitamin D, especially in months with little sunlight, if you have a diagnosed vitamin D deficiency or if you have osteoporosis.
Safe levels of vitamin D unclear
“But it should be understood that there is no single consensus on how much vitamin D we ultimately need and, more importantly, what amounts might cause harm,” Dr. Nissen cautions. This could prove to be a problem for those who take high amounts of the vitamin in hopes of better health. It is purely a gamble, he says.
No vitamin D without a doctor’s recommendation
“The bottom line is that you shouldn’t take vitamin D supplements unless your doctor, or health care professional, advises you to do so,” the cardiologist concludes. In addition, a research team at the University of California San Diego recently showed that it probably matters less how much vitamin D you take in through sunlight or supplementation, but how well your body is able to convert precursors into active vitamin D. You can read more about this in the article: False Vitamin D Levels? Only gut bacteria show true value.