Actually anyone who tries to give advice on diets- such as caloric level, balance of nutrients, proper amount of vitamins needed (especially if to an athlete), type of diet to follow, amount of weight to gain or lose, can be sued if they are not a registered dietitian/nutritionist and they try to give out diet advice, i.e. sports trainers- they can not call themselves nutritionists nor give out more than basic information, unless they are certified- my trainer was aware of this- one of the few. A pharmacist can give advice about food and drug interactions, or the difference between vitamin products. I would not advise them to try to tell a client what diet is best or anything more complicated than basic nutrition- i.e. correct vitamin C level or too avoid too much Vitamin A. Pharmacy students do not receive enough nutrition education to do that. I think they gave us 3 lectures in biochem and a good bit of what the professor said was incorrect. Same goes for med students- they get very litttle info on nutrition (unless they do a fellowship in it). One of my friend's who is a doctor said he will always leave that up to the dietitian b/c he did not have enough training in it. Nutrition is a pain in the butt area b/c everone thinks they are an expert in it when in fact very few are. Leave this area to those who are trained in it- the dietitians- they are the ones most current on nutrition information.
Hpe this helps- I feel qualified to answer given I am a pharmacy student as well as I have a BS and MS in nutrition and am a registered dietitian/licensed nutritionist.
P.S. the correct way to spell dietitian is like that- not dietician- that way is no longer used nor has been for a long time- it is antiquated.