These findings didn’t surprise Michael F. Holick, MD, PhD, a professor of medicine, physiology, and biophysics at Boston University School of Medicine who has studied the dangers of low vitamin D levels for years.
“It is estimated that many of the genes that regulate cardiovascular health are directly or indirectly regulated by vitamin D,” says Dr. Holick, author of the forthcoming book The Vitamin D Solution. “We know that vitamin D regulates blood pressure, and it is very important for maintaining good heart health.”
Vitamin D is also essential to the brain, which contains receptors for the vitamin, says Dr. Holick. “The new research is confirming previous observations that vitamin D deficiency increases the risk of depression,” he explains.
In addition to heart disease and depression, vitamin D deficiency has been linked to a host of chronic diseases, including some types of cancer, osteoporosis, diabetes, Alzheimer’s disease, schizophrenia, and some autoimmune disorders.
Although further research is needed to confirm that a shortage of vitamin D in fact links depression to heart disease and stroke, May says that more aggressive monitoring of vitamin D levels could help improve disease outcomes in the meantime.
“Even a moderate deficiency of vitamin D is associated with cardiovascular disease and death; therefore, screening and treatment is very important,” says May. “Since both are simple and relatively inexpensive, prevention of vitamin D deficiency should be cost-effective and may ultimately be able to save more lives.”
Likewise, she adds, “patients with depression may need to be more aggressively screened and treated for vitamin D deficiency since they are at higher risk for cardiovascular events.”
These studies come as the Institute of Medicine (IOM), an independent organization that advises the U.S. government on health and medical matters, is considering new recommendations for vitamin D intake. Currently, the dietary reference intake for vitamin D is 200 international units per day (IU/day) for adults ages 14 to 50, 400 IU/day for adults 50 to 71, and 600 IU/day for those older than 71.
Dr. Holick says the IOM should raise the limit on the amount of vitamin D currently deemed safe, or tolerable, which now stands at 2,000 IU/day for adults.
“If we raise it, more food can be fortified with vitamin D and fortified at a higher level,” he says. “We think [2,000 IU/day] is the baseline of what we need to take, not the upper safe limit.”
Dr. Holick advocates raising the daily limit to 10,000 IU. Many researchers agree and have suggested that the toxic level of vitamin D is closer to 10,000 IU/day.
Unlike May, however, Dr. Holick does not think that screening for vitamin D deficiency is necessary.
“We should all be taking supplements of vitamin D,” he says. “There’s no downside to increasing vitamin D intake, and if it does turn out that there is a benefit, you’re ahead of the game.”
Comments (3)
This paragraph is confusing. Should the toxic level be higher?
“Dr. Holick advocates raising the daily limit to 10,000 IU. Many researchers agree and have suggested that the toxic level of vitamin D is closer to 10,000 IU/day.”
This is incomplete and confusing. How much skin area needs to be exposed for ten to fifteen minute a day? Just the hands and face? Upper body, whole body? What?
People have always known that vitamins and proper nutrients can contribute to a more healthy heart. A new study by researchers at the Heart Institute at Intermountain Medical Center in Salt Lake City claims that Vitamin D, in particular, has strong correlations to healthy heart, and that a deficiency of Vitamin D may substantially increase one’s risk for stroke and heart disease.