Regarding which nutritional supplement to take, a doctor could give one the necessary diagnosis and prescription. Taking any nutritional supplement in random is not recommended for an overdose or a wrong choice could complicate things to a worse extend. Further, one must also realize that the nutritional supplement that worked wonders for others may not be effective for one and vice versa. We all are been made differently, and so are our body's nutritional demands. The dose and type of nutritional supplements required may vary from person to person.
Finally, before purchasing any over the counter nutritional supplement - on prescription - make sure that the one you pay for is a genuine make and not a spurious one. Checking the quality certification seal would help one to discern chalk and cheese. Remember, as it is directly related to our system, one cannot afford to make a wrong choice here. After all, health is wealth!