Direct exposure of the skin (i.e., hands, face, arms, etc.) to sunlight stimulates the body to manufacture vitamin D. However, both clothing and use of a sunscreen prevent the ultraviolet light that triggers the formation of vitamin D from reaching the skin. Depending on latitude, sunlight during the winter may not provide enough ultraviolet light to promote adequate vitamin D production. At other times during the year, even 30 minutes of exposure per day will usually lead to large increases in the amount of vitamin D made. If it is difficult to get sunlight exposure, full-spectrum lighting can be used to stimulate vitamin D production.