We spoke with a pair of cousins, one an Army veteran, the other a current member of the Navy, about some of the toughest situations they've found themselves in. Army basic training, according to Mates, is all about discipline. It's about knowing your role and not stepping out of line. And if you do, well, you pay a price. Mates said, In basic training, they call it 'getting smoked.' Push-Ups until you puke. I was always getting smoked.
Caffine is the most popular and probably the most studied of all drugs, and serious adverse effects in real life have resisted demonstration. There are pop claims about caffeine interfering with absorption of iron and vitamin d; if there were any real effect on real human beings, it would be obvious by now.
Unlike protein, carbohydrates and fats, vitamins do not yield usable energy when broken down - they are truly calorie free. However, they assist the enzymes that release energy from carbohydrates, proteins and fats, while providing no energy themselves. This does not mean vitamins are not important! Although the vitamins themselves don't provide energy, many are required for chemical reactions that do produce energy. In this sense, vitamins can give you energy. Vitamins are substances the body needs in small amounts to support most body functions and prevent disease.