Vitamin D in its inactive form is found in a variety of food, particularly in oily fish such as sardines, salmon, tuna and mackerel. Vitamin D is highly concentrated in cod liver oil. In some countries some dairy foods such as milk and margarine are fortified with vitamin D.

The majority of our vitamin D is obtained from the action of the sun on ours skin which encourages the conversion of pre-vitamin D into a compound which the body can then go on to utilise.

The third source of vitamin D is regular vitamin supplements either in the form of pure vitamin D capsules or injections, contained within multivitamin capsules or given as a preparation containing calcium and vitamin D