Natural vitamins are better than synthetic ones

This is true, in a way. Although vitamins can be synthesised to be chemically identical to those found in food, the food itself lends special properties to essential nutrients such as vitamins. For example the physical properties of food can alter the availability of the nutrient to the body. Also, other nutrients and non-nutrient components of food can influence each other ( see OYSTERS CAN TURN YOU ON). Occasionally, the chemical form in which a vitamin can be presented in pill form cannot equate with that in food, because of stability or other problems of formulation. An example is folic acid, which is not found in food in the form in which it is supplied in pills.

What is natural about a vitamin, is that it is found in food! It is nonsense to talk about natural vitamins when they come in pills.