A study among women in their 20s who use sunscreen more than three times a week has found they may have a deficiency of vitamin D in their blood.
The study was carried out by a team of researchers including those from Osaka Shoin Women's University. The team surveyed the frequency of sunscreen use and eating habits of a total of 101 women including students at the university starting in May 2016 for a period of one year.
The results showed that the average blood concentration of vitamin D for the women who used sunscreen at least three times per week fell below the standard set by the Ministry of Health, Labor and Welfare -- 20 nanograms per milliliter of blood -- throughout the year. These women were therefore considered deficient in vitamin D. It was also found that the concentration of vitamin D in their blood was a great deal lower than that of women in the 1980s.
"Women have a tendency to synthesize less vitamin D from sunlight because they use sunscreen products," said research team member and Osaka Shoin Women's University professor Naoko Tsugawa. To counter the risk of deficiency, Tsugawa says women should make a conscious effort to eat foods rich in vitamin D, such as salmon.
Vitamin D is produced in the body when bathing in UV rays contained in sunlight, and provides basic nutrients for bone formation. A deficiency of the vitamin, while not making people immediately ill, may result in an increased risk of osteoporosis and other diseases. The yearly standard is set by the health ministry for bone and overall health.