Mushrooms: another natural source of vitamin D

 Eating mushrooms that have been exposed to the sun can increase levels of vitamin D in the blood as effectively as taking supplements of vitamin D2 or D3, says a recent study from Boston University School of Medicine.

Thirty healthy adults were split into three groups for 12 weeks during the winter months (when the volunteers would have been getting limited exposure to vitamin D from sunlight). One group received 2,000 units of vitamin D3, another was given 2,000 units of vitamin D2 and the third group received 2,000 units of powder from mushrooms containing vitamin D2.

Blood levels of vitamin D increased for all three groups, plateaued after seven weeks and stayed at the same level for the last five weeks of the study.

There was no significant difference in vitamin D levels between the three groups, so the mushroom extract was as good at improving vitamin D levels as the supplements.

“We are talking about regular mushrooms,” says Dr Michael Holick who led the study. “Just take them out of the packaging and place them in the sunshine. It doesn’t matter which way up they are, after about 30 minutes they should produce a good source of vitamin D. Cooking does not affect vitamin levels. If anything, it makes it far easier to absorb the nutrient.”

Vitamin D keeps bones and teeth healthy; natural sources traditionally cited as high in vitamin D include oily fish and eggs. The results of the current research do suggest that mushrooms (that have been exposed to the sun) could be added to the list, but the study was small and needs to be replicated in larger numbers of people.