11. Mood
Using vitamin D will put you in a better mood. This is partly because it helps to improve things like your energy levels and your insulin sensitivity, both of which will help to automatically improve your mood.
At the same time though, vitamin D will also help to combat the effects of SAD. SAD stands for Seasonal Affective Disorder and is a condition that causes people to feel depressed and low in energy when it is winter.
The theory goes that this is due to inadequate exposure to light and sun and that this causes unwanted hormonal changes. Reverse the process by increasing your vitamin D intake!