# THE PHOTOBIOLOGY OF VITAMIN D3

> **NIH NIH R01** · BOSTON UNIVERSITY MEDICAL CAMPUS · 1991 · $239,837

## Abstract

The long-term objective of this research program is to develop a
better understanding of (a) the photochemistry and photobiology of
vitamin D3 that occurs in the skin when humans are exposed to
sunlight and (b) what physiologic functions the active from of
vitamin D3 (1,25-(OH)2-D3) has on human skin.  During the past
three years, we have developed new technology that permits us to
(a) evaluate how seasonal changes affect the cutaneous production
and regulation of previtamin D3 synthesis, (b) directly investigate
the photodegradation of vitamin D3 using a high performance liquid
chromatograph that is attached to an inline tritium detector (c)
culture human keratinocytes from normal subjects and patients with
dermatologic disorders such as psoriasis in a serum-free condition
in order to evaluate the morphologic and biochemical responsiveness
of these cells to 1,25-(OH)2-D3, and (d) evaluate the clinical
effectiveness of orally or topically administered 1,25-(OH)2-D3 for
the treatment of psoriasis.  During the next grant period we plan
to use these techniques to continue our productive research program
aNd investigate in detail (1) how seasonal changes in Boston and
other cities at different latitudes around the world affect the
cutaneous production of preD3 and the photodegradation of preD3 and
vitamin D3, (2) whether the photoproducts of preD3 have any
biologic effect either on the skin or on calcium metabolism, (3)
the metabolism of some of the major photoproducts of preD3 and
vitamin D3 (including lumisterol, suprasterol 1, suprasterol 2,
5,6-trans D3) that occur when human skin is exposed to sunlight,
(4) the biochemical functions of 1,25-(OH)2-D3 on cultured human
keratinocytes with special emphasis on alterations in intracellular
calcium concentrations, phosphatidylinositide metabolism and
transglutaminase activity, and (5) the responsiveness of cultured
keratinocytes and fibroblasts to synthetic analogs of 1,25-(OH)2-
D3.  Results from these investigations should provide basic new
insights into (a) the role of sunlight in providing adequate
vitamin-D nutrition for humans and (b) the physiologic effects of
1,25-(OH)2-D3 and its analogs on healthy human skin and potential
pharmacologic effects that could be potentially used for the
treatment of dermatologic disorders.

## Key facts

- **NIH application ID:** 3157837
- **Project number:** 5R01AR036963-06
- **Recipient organization:** BOSTON UNIVERSITY MEDICAL CAMPUS
- **SAM.gov UEI:** FBYMGMHW4X95
- **Principal Investigator:** MICHAEL F. HOLICK
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1991
- **Award amount:** $239,837
- **Award type:** 5
- **Project period:** 1987-09-01 → 1994-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3157837

## Citation

> US National Institutes of Health, RePORTER application 3157837, THE PHOTOBIOLOGY OF VITAMIN D3 (5R01AR036963-06). Retrieved via MORVS 2026-10-24 from https://api.morvs.ai/grant/nih/3157837. Licensed CC0.

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