This study will evaluate how much vitamin D is present in a mushroom supplement. This supplement contains an extract from mushrooms that have been exposed to sunlight. The mushroom supplement will be compared to non-commercially available vitamin D supplements produced in a Goo Manufacturing Practices (GMP)-licensed facility.

Mushrooms have the capability to produce vitamin D in a similar way to human skin. When exposed to ultraviolet light, mushrooms will convert a precursor to vitamin D. This reaction produces large amounts of vitamin D. This study is comparing a natural source of vitamin D to a synthetic source of vitamin D and will help determine if mushrooms are a novel source for this essential nutrient.

Inclusion Criteria:

• All healthy adults, male and female, age 18-64 years

Exclusion Criteria:

• Currently taking, or having taken less than one month prior to start of study, a prescription of 50,000 IU of vitamin D2 or 2000 IU vitamin D2 or vitamin D3
• Allergy to mushrooms
• History of elevated calcium (>10.4 mg%)
• Patients with a current or recent history of severe, progressive, and/or uncontrolled renal, hepatic, hematological, endocrine, pulmonary, cardiac, neurological, or cerebral disease.
• Supplementation with over the counter formulations of vitamin D2 or vitamin D3
• Subjects with a history of an adverse reaction to orally administered vitamin D.
• Subjects who are taking oral Dilantin or glucocorticoids.
• Exposure to a tanning bed or tanning on a beach for more than eight hours with no sunscreen within 2 weeks prior to start of study.
• History of intestinal malabsorption (i.e. cystic fibrosis, fat malabsorption syndrome, Crohn's Disease, gastric bypass surgery).
• Subjects with any other condition which in the Investigator's judgment would make the patient unsuitable for inclusion in the study.