It would be good to complement your nutritional needs with fruits, vegetables, and whole grains, but some people have a special need for nutrients that can only be met through supplements. For them it necessary to consume them, as they may provide them with the following benefits- Vitamin D supplements are necessary for those older adults who don’t get proper sunlight. Vitamin B-12 supplements compensate for the need for this nutrient in older adults. Folic acid supplements are used in pregnancy to reduces the risk of birth defects of the child. They are only necessary for those who are under medication, and supplements are the only source available to them for compensating their nutritional needs.