Weight / Fat loss

any vitamin found in a pill can be found in food, with food though the vitamins will have their supporting phytochemicals. Balanced as nature intended. It has worked for how many years? /facepalm

That's great. What about lactose intolerant people or vegetarian athletes?

"In Great Britain and the United States, about 30 per cent of adult women and 40 per cent of adolescent women are iron deficient, while around 6 per cent of both groups suffer from true iron-deficiency anaemia. However, studies of athletes report higher frequencies of iron problems; research indicates that up to 19 per cent of swimmers and runners may be troubled by iron-deficiency anaemia, which can have a strongly negative impact on performance."

http://www.pponline.co.uk/encyc/female-athletes-and-iron-deficiency-anaemia-752

If you can get the proper nutrients from a food source, of course you should have the food source but this isn't always possible and that's where supplements can be used.