Unlike other vitamins, the body can produce vitamin D itself. For this reason, it doesn’t act like most vitamins in our bodies, but instead more like a hormone – a messenger substance that regulates essential physiological processes.
Between 10 and 20 percent of our vitamin D required daily intake is covered by diet. However, natural sources of vitamin D in foods are limited. The highest concentrations are found in oily fish such as salmon, herring, or mackerel. Liver, egg yolk, and some mushrooms also contain vitamin D. An effective way for the body to top up on vitamin D is through sun exposure. Here, the body can synthesise vitamin D from UVB rays, which gives it the nickname “the sunshine vitamin”. Luckily, long sunbathing sessions aren’t required, regularly spending shorter periods of time outdoors during the summer with hands, face, and arms or legs uncovered and exposed to the sun is sufficient to get enough vitamin D (sunburns have to be avoided).