Don’t believe claims about the superiority of “natural” vitamin supplements over synthetic ones. The term “natural” has no legal definition on supplement labels (or indeed on most products). In any case, vitamins extracted from plants or found naturally in foods are chemically identical to their counterparts synthesized in a lab, with only a few exceptions. For instance, the “natural” form of vitamin E (labeled d-alpha tocopherol) is indeed better absorbed by the body than synthetic E (dl-alpha tocopherol). But the reverse is true for the B vitamin folate: The synthetic form used in supplements, folic acid, is better absorbed than the folate in fruits and vegetables.
Of course, vitamins found naturally in foods are superior when you consume them in that state, since they are accompanied by other nutrients and potentially beneficial compounds that work synergistically with the vitamins. When the vitamin is extracted from the plant sources, all you have is the chemical.
See also: 8 Facts to Know About Supplements.