I dont think its safe to say ANY nutrient is not needed after a while of taking it and/or others.

Everyone is different, everyone eats different and eats food from different parts of the world. Everyone is exposed to different toxic/fungal/bacterial/parasitic loads.

At the end of the day your body needs what your body needs and no one can really determine that but you by how you feel and how you perform.

Most people never push themselves physically so are missing that critical diagnostic tool.

Its human nature to want a map. A definitive answer, a checklist to follow with specific ingredients, doses and duration but the simple fact of the matter is no such thing exists. We have rough guides to get people started but thats all they are.

The best thing one can do in my opinion is educate them selves on the basic principles of nutrition, dont buy all the hype, positive or negative. Read the test books and papers that describe the roles various nutrients play. Learn to read between the lines and realize that many studies done on nutrients are very narrow in scope and while a positive or negative report usually doesnt take into account the various nuances that are outside the very narrow focus so one must have the basic knowledge to be able to recognize that and take the results with a grain of salt.