Holland & Barrett's Pure Cod Liver Oil is high in omega 3 fatty acids and provides an excellent source of vitamins A and D. Both Vitamins A and D contribute to the normal function of the immune system Vitamin A also contributes to the maintenance of normal skin, whilst Vitamin D contributes to the maintenance of normal bones and muscle function Glucosamine is produced naturally in the body, yet there are no major food sources of this substance. Glucosamine is a major structural component within joint tissue Holland & Barrett's Pure Cod Liver Oil is high in omega 3 fatty acids and provides an excellent source of vitamins A and D. Both Vitamins A and D contribute to the normal function of the immune system Vitamin A also contributes to the maintenance of normal skin, whilst Vitamin D contributes to the maintenance of normal bones and muscle function Glucosamine is produced naturally in the body, yet there are no major food sources of this substance. Glucosamine is a major structural component within joint tissue