Bioavailability and Biological Effects of Vitamin D2 Contained in Mushroom

Overview

The purpose of this study is to compare the safety and efficacy of two different amounts of vitamin D2 (600 or 4000 International Units/day) provided by mushrooms added to one of the daily meals versus same doses of vitamin D3 provided as oral supplements sold in any drugstore in reaching adequate or optimal blood levels of 25(OH)D in people with Vitamin D deficiency and pre-diabetes (high blood sugar without full blown diabetes) or the metabolic syndrome. Metabolic syndrome is the name of a group of risk factors that raise the risk for heart disease and other health problems, such as diabetes and stroke as described by the US department of Health and Human Services. This study will also attempt to demonstrate and compare the effect of the intervention with above two doses of vitamin D on blood levels of tests that show inflammation.

Poor vitamin D status is now considered epidemic in North America. In addition to its effects on bone metabolism, Vitamin D has several other important biological effects including modulating the immune system, stimulating the production of insulin and decreasing renin production in the kidney. Furthermore, the active metabolite of vitamin D, 1,25 dihydroxyvitamin D (1,25(OH)2D), is a very potent inhibitor of cellular proliferation and inducer of terminal differentiation and vitamin D deficiency has been associated with higher prevalence of cancer, autoimmune diseases, including multiple sclerosis, rheumatoid arthritis, type 1 diabetes and hypertension. The current recommendations for dietary vitamin D in North America are much too low to maintain optimal levels of 25(OH)D associated with disease prevention. The majority of circulating 25(0H) D originates from cutaneous synthesis upon exposure to adequate sunlight. However, seasonal changes, living at high latitudes or low polluted altitudes, dark skin pigmentation and aging are among the many factors that can impede this process requiring periodic reliance on dietary sources to supply the precursor to 25(OH)D. In November of 2010, the Institute of Medicine (IOM) of the National Academy of Science established new DRI values for vitamin: EAR (Estimated Average Requirement) of 400 IU (10 µg; RDA ( Recommended Daily Intake) of 600 IU (15µg) for adults up to 70 years of age, and an UL of 4000 IU (50µg) (21). The IOM also discourages the taking of dietary supplements to achieve the RDA for vitamin D and encourages Americans to achieve their needed vitamin D through food sources. The proposed study will be to provide meals with one serving of fresh mushroom per day that could have two different levels of vitamin D2 in it (600 IU or 4,000 IU/day, which are the 2011 currently recommended RDA to age 70 AI and UL, respectively) for four months and test both the bioavailability of vitamin D in mushroom, as reflected in blood 25(OH)D levels, as well as the effect of vitamin D on markers of disease (e.g. C-reactive protein (CRP), Hemoglobin A1c, etc). The vitamin D2 amount in mushrooms can easily be manipulated just by adjusting the time and distance of their UVB exposure. Two groups will be compared with controls who will receive the same dose of vitamin D3 in the form of tablets commercially available (600 IU or 4000 IU/day).