cloud cover, skin tone, clothing, sunscreen use, and how much time you spend outdoors.
Food can also provide vitamin D, but naturally rich food sources are limited. Harvard’s Nutrition Source lists fatty fish, fish liver oils, egg yolks, cheese, beef liver, UV-exposed mushrooms, and fortified foods such as some cereals and milks as sources of vitamin D.
This is why some people use supplements, especially during months when sunlight is weaker. The NHS says that from autumn and winter, people may need vitamin D from food or supplements because sunlight
