Is vitamin D3 really best? New research says perhaps not.
Types Of Vitamin D
Did you get your dose of the sunshine vitamin today? New research from the Boston University School of Medicine shows that you may be able to get all the vitamin D you need in a synthetic- or veggie-based supplement.
You’ve probably heard conflicting messages about vitamin D, including what form of D is best: D3 (naturally present in animal products and many supplements) or D2 (the synthetic version of the vitamin in some supplements and fortified foods).
The new BU study re-ignites the debate: Healthy adults who took a supplement of 2,000 IU of vitamin D2 or a D2-based mushroom powder raised their blood levels of vitamin D just as much as people taking the same amount of a D3 supplement. (The mushrooms were exposed to ultraviolet light, which increases their levels of D.)
That’s significant because it goes against some previous studies showing D3 to be more useful to the body. One, published in 2011 in The Journal of Clinical Endocrinology & Metabolism, found that D3 supplements were 87% more potent in raising vitamin D levels in the blood compared to a D2 supplement of the same dose.
“Whether vitamin D3 is more effective than D2 is still under investigation,” says Erin LeBlanc, MD, MPH, a researcher at the Kaiser Permanente Center for Health Research in Portland, Oregon, who has studied vitamin D but was not involved in the mushroom research. “Some studies have found vitamin D3 to be more effective, especially when doses are taken on a less than daily basis, such as every week or every month. However, other studies have found that they are both equally effective,” she says.
Until more is known, it’s okay to get your vitamin D as D3 or D2, LeBlanc says. The current RDA for vitamin D is 600 IU, but the Institute of Medicine suggests up to 4,000 IU a day is safe. Taking more than these recommendations isn’t advised: Research by Johns Hopkins University School of Medicine last year linked very high blood levels of vitamin D to increased inflammation that can increase your risk of heart disease, so it’s best to check with your doctor about your individual needs.
If you don’t eat animal-based foods, you can find D2 in fortified products, like soymilk; many brands pack 30% of your daily value per cup. To be sure it’s D2, read the ingredients label and look for its official name “ergocalciferol.”