Vitamin A is a fat-soluble vitamin, also known as retinol because it produces pigments in the eye's retina. The eye needs a specific metabolite - retinal - a light-absorbing substance that is crucial for scotopic vision (low-light vision). Vitamin A is also important for healthy teeth, skeletal tissue, soft tissue, the skin, and mucous membranes.
Vitamin B(I am not writing because there are 12 types of Vitamin B)
Vitamin D is a nutrient that the body needs in small amounts to function and stay healthy. Vitamin D helps the body use calcium and phosphorus to make strong bones and teeth. It is fat-soluble (can dissolve in fats and oils) and is found in fatty fish, egg yolks, and dairy products. Skin exposed to sunshine can also make vitamin D. Not enough vitamin D can cause a bone disease called rickets. It is being studied in the prevention and treatment of some types of cancer. Also called cholecalciferol.