Another area of confusion for many people is how skin is affected by ingesting foods or drinks that contain key ingredients (for lack of a better word) versus applying them topically to the skin. For example, we know that Vitamin C is a wonderful antioxidant for the skin, but does that mean you should eat an orange or get a Vitamin C serum to apply?
When it comes to skin care, topical application reigns supreme. Serums and creams have isolated the key ingredient and included it at a higher concentration than the skin would likely ever receive from orally consumed oranges, even if you ate a bunch of them. This is because the vitamin would go to many different areas of the body if you were to eat (or drink) a Vitamin-C rich food, which is still great for your health but may have little to no effect on your skin.
Eating a healthy and balanced diet will likely improve your skin overall, so keep up the good work, but if you are trying to target a specific skin concern, it is best to get a topically applied product for the best results.