The purpose of this study is to evaluate the effect of heat on the bioavailability of vitamin D in industrially fortified mozzarella cheese baked with pizza.

With a growing body of evidence, the Institute of Medicine (IOM) conducted a thorough review of all available evidence to publish a report on Dietary Reference Intakes (DRIs) for calcium and vitamin D. In the absence of adequate sun exposure, acquiring the new RDA of 600-800 IU/d for vitamin D through diet alone is difficult. There is a need to increase dietary sources of vitamin D for Canadians.

In a double blind, randomized trial, our objective was to assess the effect of high temperature pizza baking on the bioavailability of vitamin D3 fortified Mozzarella cheese. We tested the following hypotheses, set a priori: 1) vitamin D3 is bioavailable from pizza baked with fortified Mozzarella cheese and heat does not significantly break down vitamin D3; and 2) the change in serum 25(OH)D (from baseline to 10 wk) will be significantly greater in the high-dose vitamin D treated group (28000 IU/wk) compared to the low dose vitamin D-treated group (200 IU/wk).

Inclusion Criteria:

• Healthy males and females between ages 18-70 years

Exclusion Criteria:

• Use of vitamin D supplements in excess of 1000 IU/day
• A history of any medical disorder that might effect vitamin D or mineral metabolism
• Use of medications that could interfere with vitamin D metabolism
• Potential for sun exposure ( i.e travel to a sunny destination of use of tanning beds) within the month prior to or during the study
• History of hypercalcemia
• Unwillingness to return for follow up