DIETARY MODULATION OF IMMUNE FUNCTION AND OXIDATIVE STRESS
Location: Immunity and Disease Prevention Research Unit
Title: Ergocalciferol from mushrooms or supplements consumed with a standard meal increases 25-hydroxyergocalciferol but decreases 25-hydroxycholecalciferol in the serum of healthy adults
Submitted to: Journal of Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 9, 2012
Publication Date: July 1, 2012
Citation: Stephensen, C.B., Zerofsky, M., Burnett, D., Lin, Y., Hammock, B.D., Hall, L.M., Mchugh, T.H. 2012. Ergocalciferol from mushrooms or supplements consumed with a standard meal increases 25-hydroxyergocalciferol but decreases 25-hydroxycholecalciferol in the serum of healthy adults. Journal of Nutrition. 142(7):1246-1252. DOI: 10.3945/jn.112.159764.
Interpretive Summary: The U.S. food supply contains relatively few sources of naturally occurring vitamin D. Vitamin D3 is found in foods of animal origin and can be produced in the skin upon exposure to sunlight. Vitamin D2 is found in mushrooms and is also produced by exposure to sunlight. Both forms of the vitamin are active in humans. The vitamin D2 content of commercially produced mushrooms can be increased by exposure to sun or treatment with artificial ultraviolet (UV) light and such treatment may provide a needed additional source of vitamin D for the U.S. population which, overall, has low vitamin D intake. We conducted a study to determine if vitamin D2 was readily absorbed from mushrooms and converted to 25-hydroxy vitamin D2, which is the form of the vitamin that is normally found in the blood. We also measured 25-hydroxy vitamin D3 to determine the effect on vitamin D status, as indicated by the total concentration of 25-hydroxy vitamin D2 plus D3 in the blood. We fed human volunteers a standard lunch containing button mushrooms (cooked in a microwave) seven days per week for six weeks. Subjects in this study were healthy adults, the majority of whom had adequate vitamin D status and negligible intake of vitamin D2. Thirty-eight volunteers participated and were randomly allocated to four groups that received mushrooms that were treated with different levels of artificial UV light to produce different levels of vitamin D2. The four treatment groups were: a control group receiving untreated mushrooms providing 34 international units (IU) of vitamin D2/day; a group receiving low-UV mushrooms providing 352 IU/day; a group receiving high-UV mushrooms providing 686 IU/day; and a group receiving untreated mushrooms plus a vitamin D2 capsule providing 1,131 IU/day. The currently recommended vitamin D intake for adults < 70 years of age is 600 IU/day. The blood levels of 25-hydroxy vitamin D2 increased over the six week study period in all groups except the control group. However 25-hydroxy vitamin D3 decreased in these three groups by a similar amount, thus overall vitamin D status did not differ among the groups as a result of the increased intake of vitamin D2. These results indicate that vitamin D2 is highly available from mushrooms but may not improve status further in subjects who have adequate status at the beginning of the study. The reason that serum 25-hydroxy vitamin D3 decreased could not be directly determined from this study but suggests that future research should be done to determine why this occurs.
Vitamin D deficiency is common in the U.S. due to limited sun exposure and low dietary intake. Few foods naturally contain vitamin D but treatment of mushrooms with ultraviolet (UV) light increases vitamin D2 content and could provide an additional dietary source of vitamin D. We evaluated the impact of consuming UV-treated white “button” mushrooms (Agaricus bisporus) on the vitamin D status of healthy adults. Thirty-eight volunteers were randomized to four treatments taken with a standard lunch for six weeks: untreated mushrooms (n = 10, 34 IU vitamin D2/d); low-UV mushrooms (n = 10, 31 352 IU/d); high-UV mushrooms (n = 9, 686 IU/d); and untreated mushrooms plus vitamin D2 capsule (n = 32 9; 1,131 IU/d). Serum total 25(OH)D at baseline was 83 ± 38 nmol/L. Serum 25(OH)D2 was 2.4 ± 2.0 33 nmol/L and increased in the three treatment groups (p < 0.05). Mean increases were 1.2 ± 5.2, 13.8 ± 7.3, 12.7 ± 3.7, and 32.8 ± 3.3 nmol/L, respectively. Serum 25(OH)D3 decreased proportionally in the same groups (p < 0.05). Mean decreases were -3.9 ± 16.3, -10.4 ± 6.4, -20.6 ± 14.6, and -29.5 ± 15.9 36 nmol/L, respectively. Serum 24,25(OH)2D3 did not differ by group suggesting that vitamin D3 catabolism was not affected by vitamin D2 intake. Total serum 25(OH)D decreased in the treatment groups but changes did not differ significantly from the control group. In summary, vitamin D2 from UV-treated mushrooms was absorbed and metabolized to 25(OH)D2 but did not improve vitamin D status because serum 25(OH)D3 decreased proportionally.