Explanation:

The two major classes of vitamins are fat soluble and water soluble. Vitamin C and all of the B vitamins - thiamine, riboflavin, niacin, vitamin B6?, folate, vitamin B12?, biotin and pantothenic acid share similar characteristics because they are all water soluble. The body has a limited ability to store these vitamins so they need to be continuously replenished by the diet. Water-soluble vitamins are absorbed by the digestive tract into the bloodstream, metabolized and then excreted by the kidneys in the urine.