Mushrooms May Be a Better Source of Vitamin D than Supplements

Researchers from Boston University School of Medicine (BUSM) have recently discovered that eating mushrooms that contain Vitamin D2 may actually be as effective at increasing and maintaining vitamin D levels (25-hydroxyvitamin D) as taking supplemental vitamin D2 or vitamin D3.

Vitamin D is a crucial necessity used for good bone health and muscle strength. The nutrient also helps to keep the immune system regulating by fighting off such infections as the flue and reducing the risk of many common diseases, including cancer, cardiovascular disease, depression and diabetes.

The study to be presented consisted of 30 healthy adults who were randomized to take capsules containing 2000 International Units (IU) of vitamin D2, 2000 IU of vitamin D3 or 2000 IU of mushroom powder containing vitamin D2 once a day for 12 weeks during the winter. Baseline serum 25-hydroxyvitamin D [25(OH)D], a measure to determine a person's vitamin D status, were not significantly different among the groups. The serum 25(OH)D levels among the three groups gradually increased and plateaued at seven weeks and were maintained for the following five weeks. After 12 weeks of the vitamin D supplements, serum 25(OH)D levels were not statistically significantly different than those who ingested 2000 IU of vitamin D2 in mushroom powder.

"These results provide evidence that ingesting mushrooms which have been exposed to ultraviolet light and contain vitamin D2, are a good source of vitamin D that can improve the vitamin D status of healthy adults. Furthermore we found ingesting mushrooms containing vitamin D2 was as effective in raising and maintaining a healthy adult's vitamin D status as ingesting a supplement that contained either vitamin D2 or vitamin D3," said Michael F. Holick, PhD, MD, the principal investigator of the abstract.

"These results confirm other studies that have demonstrated that ingesting vitamin D2 either from fortified orange juice, a supplement or a pharmaceutical formulation were all capable of increasing total circulating 25(OH) D concentrations for at least 3 months, and up to 6 years," Holick added, the senior author of the study. "The observation that some mushrooms when exposed to UVB light also produce vitamin D3 and vitamin D4 can also provide the consumer with at least two additional vitamin Ds."

Another part of the study showed that researchers were able to determine how mushrooms make vitamin D2 and found that the process is very similar to what occurs in human skin after sun exposure. They were also able to show that mushrooms not only produce vitamin D2, but can produce vitamin D3 and vitamin D4.

This study has shown that researchers believe mushrooms may be incorporated into a diet as another good source of vitamin D.

The study is available on line concurrently in the journal Dermato-Endocrinology.