Vitamin D is quite unique. Both a vitamin we consume and a hormone we make, it is often referred to as the sunshine vitamin because the process of making it in our bodies is initiated by sunlight hitting our skin (and is ultimately synthesized in the kidneys).
We can also get vitamin D from food sources. But the truth is, it’s actually pretty difficult to get adequate vitamin D from foods. Few foods are actually good sources (fatty fish like tuna and salmon are!), and most of those sources are fortified (like dairy products and breakfast cereals). Because of this, vitamin D has recently been the subject of much research and discussion.It is thought that 1 billion people worldwide have low blood levels of vitamin D. This is especially problematic for those living in northern latitudes where the type of sunlight exposure necessary for adequate vitamin D synthesis isn’t up to par for the majority of the year.