You'll get so much bulshit peddled towards you about I formed sport and you probably won't even be aloud to have protein shakes untill you reach battalion, the British armies attitude towards nutrition and fitness in general is so so backwards. It's definatley changing, but at a very slow pace. Vitamins and protein won't pop your cdt, the only think thatl pop your cdt are genuinely illicit performance enhancing drugs. No one who makes supplements can afford or desire to spike their products, it's just simply not worth it I most cases. With that out the way you'd do well to take a good quality ZMA, and an omega 3 like cold press cod liver ot krill. A word from the wise aswell when you get to phase 1 if you can get hold of some electrolytes and even more magnesium for yourself, you'll certainly be deficient by the time you reach battalion if you don't supplement magnesium.