Inclusion Criteria:

1. Light-skinned volunteers (Caucasians including Hispanics with slightly darker
complexion)

2. 18 years of age (5 men and 5 women)

3. Resident in the State of New Mexico

4. Indoor workers with no significant history of prolonged, excessive sun exposure

5. Willing to have a monthly blood draw

6. Willing to fill out the sun diary every day on different indoor/outdoor activities.

7. During the project time period potential pregnancy of women volunteers would change
the risk category of the participants, and that is a reportable event to UNM HSC HRRC
and the Clinical Trial Office.

Further explanation of the inclusion criteria:

This pilot study is intended to evaluate the dose-response associations between measured
UV exposure and individual serum 25 (OH)-vitamin D levels. To date, there is little data
and a great deal of mis-information about vitamin D. Caucasians have a variety of skin
types and melanin production. This pilot study is unfunded and we know that there is
extreme heterogeneity among Caucasians in their absorption of UVB and subsequent synthesis
of vitamin D. Among our volunteers 2 participants with Hispanic ethnicity are represented
as well. Darker-skinned individuals, such as African Americans, produce considerably less
vitamin D, based on the bone health literature. Inclusion of African Americans will be
critical in the future as we develop our understanding of the relationship between vitamin
D and UV exposure. Our collaborator, Elizabeth Jacobs at the University of Arizona, is
currently conducting a pilot study to evaluate UV and serum vitamin D among individuals
with darker pigmentation. The motivation for our pilot study has to do with the balance
between vitamin D and sun exposure as a risk-benefit assessment for the development of
melanoma. Asians and African Americans do develop melanoma, but at a rate ten times less
than Caucasians and it does not appear to be related to sun exposure; thus, to include
them at this time would not allow us to focus on the medically-related issue.

Exclusion Criteria:

1. Diet high in oily fish (e.g. eating cod liver or sardines oil conserved products more
than 2-3 times/week)

2. Oral vitamin D supplementation (over 1,000 IU/day amount)

3. Tanning bed use.

4. Existing pregnancy