According to a new study, almost half of all Australians working indoors could come out of the winter months lacking in vitamin D.
In the study, blood vitamin D concentrations of about 100 office workers were analyzed (1). The results showed that 42 percent of the participants were deficient in the vitamin by the end of winter. In addition, one in three had low levels over summer. The lowest levels of vitamin D were measured in people with very dark skin: 90 percent were deficient by the end of winter.
Researcher Prof. R. S. Mason commented that while there are no short-term symptoms indicating a deficiency, a lack of vitamin D puts people at greater risk of osteoporosis and poor muscle function later in life. Those with very fair skin tend to be lacking vitamin D, as they avoid the sun because of its potential harm. She recommended getting out in the sun in the middle of the day in winter with as much skin exposed as possible. However, the same rays necessary for vitamin D synthesis in the skin can also cause skin damage, she warned. Mason added that according to her own research, vitamin D compounds formed in skin by the action of UV light contribute to photoprotection from within, including a reduction of DNA damage and UV-induced suppression of the immune system.