2. Limited Exposure to Sunlight
As mentioned earlier, the sun’s rays are the primary way a person gets vitamin D, because when the skin is exposed to sunlight it triggers the body to make the nutrient from cholesterol. This may be a particular issue for those who “are homebound, live in northern latitudes, wear long robes or head coverings for religious reasons, or have an occupation that prevents sun exposure,” says WebMD.
Although, MedicineNet.com adds that even in places that get plenty of sunshine, a deficiency may occur because the SPF in sunscreen decreases vitamin D synthesis, and “Most adults work indoors and wear more clothing during the work week, which leaves only about 10%-15% of their body exposed to UV for short periods.”