Background: Randomized controlled trial (RCT) data on the response of serum total 25-hydroxyvitamin D [25(OH)D] in healthy participants consuming UV light-exposed edible mushrooms are limited and mixed.
Objective: The objective was to undertake a systematic review and meta-analysis of responses of serum 25(OH)D [and serum 25-hydroxyergocalciferol, 25(OH)D2, and serum 25-hydroxycholecalciferol, 25(OH)D3, if available] to consumption of UV-exposed mushrooms by healthy participants. Biobanked sera from one RCT (originally analyzed by immunoassay) were reanalyzed by LC-MS/MS to generate serum 25(OH)D2 and serum 25(OH)D3 data.
Methods: Ovid MEDLINE, EMBASE, and Cochrane CENTRAL were searched for RCTs of UV-exposed mushrooms and data on serum 25(OH)D. Studies were screened for eligibility, and relevant data were extracted. Serum 25(OH)D data were re-analyzed by ANOVA and paired t tests.
Results: Our structured search yielded 6 RCTs meeting our inclusion criteria. Meta-analysis of all 6 RCTs showed serum 25(OH)D was not significantly increased (P = 0.12) by UV-exposed mushrooms, but there was high heterogeneity (I(2) = 87%). Including only the 3 European-based RCTs [mean baseline 25(OH)D, 38.6 nmol/L], serum 25(OH)D was increased significantly by UV-exposed mushrooms [weighted mean difference (WMD): 15.2 nmol/L; 95% CI: 1.5, 28.8 nmol/L, P = 0.03, I(2) = 88%], whereas there was no significant effect in the 3 US-based RCTs [P = 0.83; mean baseline 25(OH)D: 81.5 nmol/L]. Analysis of serum 25(OH)D2 and serum 25(OH)D3 (n = 5 RCTs) revealed a statistically significant increase (WMD: 20.6 nmol/L; 95% CI: 8.0, 33.3 nmol/L, P = 0.001, I(2 =) 99%) and decrease (WMD: -13.3 nmol/L; 95% CI: -15.8, -10.7 nmol/L, P < 0.00001, I(2) = 0%) after supplementation with UV-exposed mushrooms.
Conclusions: Consumption of UV-exposed mushrooms may increase serum 25(OH)D when baseline vitamin D status is low via an increase in 25(OH)D2 (24.2 nmol/L) and despite a concomitant but relatively smaller reduction in 25(OH)D3 (-12.6 nmol/L). When baseline vitamin D status is high, the mean increase in 25(OH)D2 (18.3 nmol/L) and a relatively similar reduction in 25(OH)D3 (-13.6 nmol/L) may explain the lack of effect on serum 25(OH)D.
Keywords: 25(OH)D2; 25(OH)D3; RCT; UV exposed; edible mushrooms; vitamin D.
© 2016 American Society for Nutrition.