Evaluation of the bioavailability and metabolism of vitamin D2 in a mushroom supplement compared to supplemental vitamin D2 and supplemental vitamin D3

Mushrooms can produce vitamin D2 when exposed to sunlight or ultraviolet radiation. The goal of this research was to determine if ingesting dried white button mushroom extract (Agaricus bisporus) containing vitamin D2 (Monterey Mushrooms, Inc., CA) was effective at increasing and maintaining vitamin D status when compared to supplemental vitamin D3 and supplemental vitamin D2. Seventy five healthy adults were enrolled in the study (25 male, 50 female, mean age 29.9 years) and were randomized to ingest capsules containing 2000 IU vitamin D2, 2000 IU vitamin D3, 2000 IU mushroom vitamin D2, or a capsule containing an equivalent amount of mushroom powder once a day for three months during the winters of 2012 and 2013 in Boston, Massachusetts. Baseline serum total 25(OH)D levels were not significantly different between the groups 19.6 ± 2.1 ng/mL, and 23.9 ± 2.1 ng/mL, and 23.8 ± 2.3 ng/mL, 22.2 ± 2.0 ng/mL for the supplemental vitamin D2, mushroom powder, supplemental vitamin D3, and mushroom vitamin D2 groups respectively. Serum 25(OH)D levels gradually increased and plateaued at 7 weeks and were maintained for the following 5 weeks. At the end of 12 weeks, the change in serum 25(OH)D concentrations was statistically significantly different between groups taking supplemental vitamin D2 and mushroom powder (p < 0.001), supplemental vitamin D3 and mushroom powder (p < 0.0001), mushroom vitamin D2 and mushroom powder (p = 0.01). Serum 25(OH)D concentrations increased by 75 ± 20%, 11 ± 4%, 98 ± 10%, and 66 ± 19% in the supplemental vitamin D2, mushroom powder, supplemental vitamin D3, and mushroom vitamin D2 groups respectively. Serum 1,25(OH)2D concentrations in all groups did not change over the course of 12 weeks. Groups taking supplemental vitamin D2 or mushroom vitamin D2 had an increase in serum concentrations of 1,25(OH)2D2 concentrations with an equal decrease in 1,25(OH)2D3. These results indicate that 1,25(OH)2D concentrations are tightly regulated regardless of the source of vitamin D. Thus, mushroom vitamin D2 is effective at increasing and maintaining serum 25(OH)D and 1,25(OH)2D levels similar to supplemental vitamin D2 and supplemental vitamin D3. Supported by the Mushroom Council