Study finds summer sun alone may not resolve vitamin D deficiency

ANBAR, Iraq — Sun exposure during summer may not be sufficient on its own to correct vitamin D deficiency in certain high-risk groups, according to research published in the European Journal of Clinical Nutrition. The study examined roughly 300 people, with older adults and individuals with darker skin making up the largest shares of the sample. The researchers found that 55 percent of participants were elderly and 72 percent had darker skin, and that vitamin D levels remained low in these groups even during the summer months. They identified advancing age, higher skin melanin density, limited direct sun exposure and the use of sunscreen as factors that reduce the body's ability to produce vitamin D. According to the Mayo Clinic, vitamin D is critical for maintaining bone and dental health, supporting calcium absorption, aiding muscle function and keeping the immune system working properly. The study's authors noted that vitamin D synthesis varies with duration of exposure, time of day, the amount of skin uncovered, skin tone, age and the intensity of ultraviolet radiation at a person's location. Researchers recommended that people at risk rely on more than sunlight, suggesting foods such as salmon and sardines, egg yolks, fortified milk and cereals, and, when appropriate, doctor-supervised supplements. They said summer vitamin D intake should be tailored to individual blood levels and health status, and that some elderly individuals with diagnosed deficiencies may need to continue supplementation under medical supervision.