According to the US Department of Health and Human Services, sunscreen does not prevent vitamin D from being produced, at least at SPF 15. "There has been some

According to the US Department of Health and Human Services, sunscreen does not prevent vitamin D from being produced, at least at SPF 15. "There has been some concern that use of sun protection factor (SPF) of 15 results in vitamin D deficiency. However, a randomized trial in people over 40 years of age found that sunscreen use over the summer had no effect on 25-hydroxyvitamin D3 levels." Source: http://www.ahrq.gov/clinic/3rduspstf/skcacoun/skcarr.htm http://www.ahrq.gov/clinic/3rduspstf/skcacoun/skcarr.htm