What's the difference between vitamins and supplements?
The first part of 'vitamin' is 'vita', meaning 'life'. The second part, 'min', is derived from the longer word 'Amine', which is the name of a class of compounds to which vitamins were originally thought to belong.
If we look at the definition of supplement, it means "something that completes or enhances something else when added to it."
In effect a health supplement, such as a vitamin D supplement, is a method of aiding, enhancing or simply supporting your health.
Contained within a supplement is the actual vitamin, which in the case of vitamin D can only be obtained naturally by your body through sunlight.