There are so many medical studies out there today that it is hard to keep up. In fact, about 8,000 medical articles are published every day. You can google and find a medical study to prove almost any position you are trying to prove which can be very confusing. What I have done in my practice, is try to look at common sense and what I see in my own practice. Take for instance a recent study saying low vitamin C is useless in serious infections. They gave hospitalized patients with sepsis (a condition in which bacterial infection have overwhelmed the blood or tissue in the body so that the body is going into shock and this can be deadly) they gave 1,500 mg of vitamin C every 6 hours and noted it did not help the patients. They then said vitamin C is useless for fighting infection. First of all, any one with sepsis in the hospital should be on high dose antibiotics. Second, even the National Institute has done studies with high dose vitamin C for cancer and have noted how great it works on patients. My own patients, myself, and my family use large doses of vitamin C and can all attest to how effective it is in our own health and its ability to help the body fight infection. I often look at these studies and see how they use very low doses of natural product in very serious conditions and almost with glee announce they failed and are therefore useless.
Vitamin D is another natural product that the medical articles seem to say is not that helpful. Vitamin D they feel is extremely toxic if the level is above 100 NG/ML. I have gone back and looked at a number of the studies and you realize the studies are poorly done. I know one study where patients with multiple sclerosis who had vitamin D levels between 250-300 did much better with their disease. My own patients with Rheumatoid Arthritis that kept their levels between 150-200 tend to have less pain. My daughter with autoimmune problems was told by the doctor that she will need antibiotics every month for the rest of her life. She is 9 now and has never been on a course of antibiotics. Her Vitamin D level runs 130-230.
It is a confusing world out there so talk to your doctor and he or she can help you navigate it.