Additionally, the new data found that vitamin D supplements do not offer the support for preventing a range of health problems as commonly believed.
Vitamin D can strengthen bones, boost immune function and support heart health; however, high doses of the vitamin do not improve heart and circulatory health for most adults as well as modest doses, according to a study funded by the National Institutes of Health.
“Only small to moderate amounts of vitamin D are needed to have optimal cardiovascular function,” said study author JoAnn E. Manson, MD, DrPH, chief of the Division of Preventive Medicine at Brigham and Women’s Hospital and Harvard Medical School. in a press release. “More is not better.”
Ongoing research has found that adults who take moderate or high doses of daily vitamin D supplements of approximately 1,000 IU have no lower risk of heart attack, stroke, or cardiovascular-related death than adults taking placebo without vitamin D.
Additionally, the new data found that vitamin D supplements do not offer the support for preventing a range of health problems as commonly believed. For example, higher vitamin D intake has not been found to prevent cancer, bone fractures, or falls, and it does not reduce knee pain, cognitive decline, or atrial fibrillation, among other conditions.
The National Academy of Medicine recommends a daily intake of 600 IU of vitamin D for people between the ages of 1 and 70 and 800 IU for adults 71 and older. However, Manson added that it is reasonable for adults who are concerned that they are not getting enough vitamin D to take a daily supplement of 1,000-2,000 IU during the COVID-19 pandemic.
With all of this information, the best way to get vitamin D is through occasional sun exposure, which includes being physically active outdoors, eating vitamin D-rich foods, and reading nutrition labels to make sure you get the right amount.
To assess heart health, researchers have conducted randomized, controlled trials, including the VITAL trial. Between 2011 and 2013, more than 25,000 adults were enrolled in VITAL, which found that high-dose vitamin D supplementation did not prevent cardiovascular events.
After an extensive review of 21 randomized trials, Manson found that both vitamin D and cardiovascular disease “show no clear benefit of vitamin D supplementation in preventing heart disease or stroke.”
Elements such as exercise, diet and inflammation levels have been targeted as reasons why adults with higher levels of vitamin D are less likely to have cardiovascular disease in observational studies.
Researchers are now focusing on how high-dose vitamin D supplements can support immune function in people with autoimmune diseases, including rheumatoid arthritis, lupus and psoriasis. Other types of research on this topic include whether vitamin D can reduce the severity of COVID-19 infections, shorten recovery, and reduce the risk of prolonged COVID-19.
Vitamin D is also being studied to see if higher intakes can slow its progression and reduce cancer-related deaths.
“There may be subgroups of patients who are at higher risk for adverse cardiovascular outcomes who may benefit from vitamin D supplementation,” said Alvin A. Chandra, MD, a VITAL investigator and assistant professor in the department in cardiology at Southwestern Medical University of Texas Center, in a press release.
Other areas of study that are assessed are:
- Skin color and its relationship to vitamin D and sun exposure
- Major diseases such as Crohn’s disease and celiac disease
- How vitamin D interacts with other nutrients
- Genetic links to vitamin D in terms of how the vitamin is metabolized and binds to receptors
Vitamin D for heart health: where the benefits begin and end. NIH. September 27, 2022. Accessed October 10, 2022. https://www.nhlbi.nih.gov/news/2022/vitamin-d-heart-health-where-benefits-begin-and-end