The device that the investigators used in this study was originally designed for tanning. From our pilot study H23521 the investigators observed that much longer times were needed to increase the production of vitamin D. As can be seen in Figure 1, our healthy adults exposed to up to 10 minutes to the Sperti lamp showed significant increases in serum 25 (OH)D levels in the subjects studied. The investigators found that 5 of the 8 subjects showed significant increases in 25(OH)D. Those with skin type IV and V demonstrated minimal responses due to the sunscreening effect of their skin pigment (Fig 2). This demonstrates that skin types IV and V may require longer exposure times to achieve the 0.75 MED dose and raise the serum 25(OH)D level. However, during this pilot study, the investigators did not observe any untoward side effects (such as skin redness) associated with exposure to UVB light with longer exposure times.