Eating mushrooms containing vitamin D2 can be as effective at increasing and maintaining vitamin D levels in the body as taking vitamin D supplements, according to a study from Boston University School of Medicine.
The findings will be presented at the annual meeting of the American Society for Biochemistry and Molecular Biology being held in conjunction with the Experimental Biology 2013 meeting in Boston.
AdvertisementVitamin D, also known as the sunshine vitamin, is crucial for good bone health and muscle strength as it reduces the risk of fracture, osteomalacia (softening of the bone because of vitamin D deficiency), osteoarthritis and osteoporosis. It also impacts the immune system to help fight against cancer, autoimmune diseases (for example, celiac disease, multiple sclerosis, rheumatoid arthritis, type 1 diabetes, Addison's disease, etc), infectious diseases, type 2 diabetes and cardiovascular diseases.
Mushrooms are one of the few plant food sources which contain ergosterol, a precursor to vitamin D2. The two major physiological forms of active vitamin D for humans are ergocalciferol (D2) and cholecalciferol (D3). Ergosterol, found in mushrooms is converted to ergocalciferol or vitamin D2 by exposure to UV light. Small amount of vitamin D2 are synthesized in the mushrooms by exposure to naturally occurring UV light during growing or processing.
The current recommended Adequate Intake (AI) for Vitamin D for most adults is 5 microgram (200 IU).
Michael F. Holick, Professor of Medicine, Physiology and Biophysics at Boston University School of Medicine and the principal investigator of this study and his colleagues recruited 30 healthy adults who were given capsules containing 2,000 International Units (IU) of vitamin D2; 2,000 IU of vitamin D3; or 2,000 IU of mushroom powder containing vitamin D2 once a day for 12 weeks during the winter.
Initially, the participants' vitamin D status, measured by serum 25-hydroxyvitamin D [25(OH)D], were not significantly different among the groups.
The 25(OH)D levels gradually increased and plateaued at 7 weeks and were maintained for the next 5 weeks in all the three groups.
After 12 weeks (end of the study), 25(OH)D levels were not significantly different in any of the group suggesting that mushroom, mushroom powder and vitamin D supplements were equally effective in maintaining and increasing vitamin D levels in the body.
"These results provide evidence that ingesting mushrooms that 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," said Holick.
"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," he added.
The researchers also found that some mushrooms when exposed to UVB light produce vitamin D3 and vitamin D4 as well thus providing the consumer with at least two additional vitamin Ds.
In their second presentation at the same meeting, Dr Holick and his team will discuss how mushrooms make vitamin D2 using a process similar to what occurs in human skin after sun exposure.
"Although it has been previously reported that mushrooms have the ability to produce both vitamin D2 and vitamin D4, through our own research we were able to detect several types of vitamin Ds and pro-vitamin Ds in mushroom samples, including vitamin D3, which is also made in human skin," they said.