| Popis: |
As a first step toward documenting efficacy of the Mark IV (Synaptic Tan, Inc., Louisville, KY, synaptictan.com) for clinical vitamin D3 augmentation we sought to determine whether in vitro photoactivation of 7-dehydrocholesterol (7-DHC) occurs. The Mark IV provides uniform illumination (± 15%) over 0.5 m2 at 60 cm utilizing non-spatial collimation with 20–100 µ pulses of UVB/UVA. The optically coated reflectors serve as highly effective bandpass filters with output ranging over 270–370 nm with little light measured above and below this range. The device delivers 1 FDA corrected MED within 1-4 minutes depending on pulse rate and distance. Glass ampoules (total 27) containing 7-DHC in methanol were exposed to 0.5, 1, and 2 MED at 30, 45, and 60 cm. Assay for preVitamin D3 (preD3), Lumisterol (L3), and Tachysterol (T3) identified a dose-dependent linear relationship for the formation of preD3 independent of distance. This confirms that “reciprocity” is preserved with 20–100 µ pulses. |
