We've all had the patient who starts a workout program and is told by the gym trainer to purchase protein powder. We have also had female patients purchase supplements on the recommendation of their hair and nail people.  I chuckle at how often the slightly informed (in this case, the gym and hair/nail folks) advice the uninformed (the average person with little interest in supplements).  When I encounter these stories, I always ask the patient if the person who made the recommendation asked any questions about their diet or supplements.  The answer is almost always no.  Meaning the gym trainer had no idea if additional protein was needed, and the salon workers were equally unaware if the amount of sulfur containing amino acids, biotin, antioxidants and other B vitamins were indicated. The slightly informed aren't the only ones to make this error. Health care professionals can inadvertently slide down this slope too. 

I just saw a man for nighttime cramps. It turned out that he had used a calcium/ vitamin D product for many years. It contained 600 mg of calcium carbonate and 400IU of vitamin D per tablet. He was advised by a chiropractor he knew that he should switch to calcium citrate, because it was a better form.  He bought a calcium citrate & vitamin D product that was labeled to provide the same amount of calcium/vitamin D as his previous product. He took one pill a day (just like he always did) and overlooked the tiny print that stating 3 tablets provided label levels. It took a few weeks for him to develop the cramps and he didn't make the connection until I explained that the new product only provided 200 mg of calcium per tablet.    I then asked if the person who made the recommendation inquired about his bone density or stomach acid.  The answer was no.  Had he asked, he would have discovered the patient did not have low stomach acid (meaning he could absorb carbonate) or low bone density (confirming that, he was absorbing the carbonate form). He elected to return to the calcium carbonate because it cost less money and required fewer pills.

A physical therapist asked a patient "Do you take vitamin C?" The man said "I take a multi and some other stuff from my chiropractor."  The PT said "You need to buy some and take 500 mg a day since you just had shoulder surgery." Had the therapist pursued the matter fully, she would have learned the fellow’s multi contained 250 mg and the 'other stuff' was a temporary injury formula his DC (me) put him on, which provided an additional 500mg of vitamin C.  Furthermore, the man has a great diet and gets around 400mg from food alone, meaning his all-source post-op vitamin C intake was ~ 1150 mg.

"You need omega 3's" is what his MD told a man I saw whose complaints were loose stools and easy bleeding. When I analyzed his diet, he averaged 10-11 servings of seafood a week, much of which was rich in omega 3's. It turned out that his doctor had no idea how much fish the patient ate. I told him to stop the omega 3’s and return in a few weeks. He called and cancelled the visit (because his symptoms were gone) and told me "I've already told 3 people to stop taking that stuff!"  What should have been a short call wasn't, since I needed to explain to a victim of 'advice without background' that he was now guilty of the same mistake.

To summarize, before making a supplement recommendation, find out what they eat and what they take. If they do take something, find out what form, what amount and if it’s working. When you follow those steps, you’ll probably make fewer recommendations, but the ones you do make will have better results.