Is it necessary to use vitamins on my skin for anti-aging? Don’t my vitamin supplements I take provide the skin benefits?

In order for vitamins to benefit the skin such as in decreasing the effects of photoaging, stimulating fibroblasts and new collagen, and providing antioxidant activity, they must be delivered to the site of action in sufficient doses. Oral supplements deliver nutrients through the bloodstream and gastrointestinal system, which limits its delivery to the skin. In fact, only about 1 percent of oral vitamin ingestion will actually reach the skin. Excess water-soluble vitamins are excreted while fat-soluble ones such as vitamin A get stored in the liver. With vitamin C for example, by the time enough is ingested to reach therapeutic levels for the skin, the body has excreted much of the vitamin. Since the skin is itself an organ capable of absorption, topically applied vitamins will deliver the molecules directly to where it’s expected to do its job while also protecting the other organs from hepatoxicity.