If you only eat meat you don't need fiber, as long as you get sufficient fat and fluids it's unproblematic to the point of being laughably regular and much more so than with any other way of eating....

You also don't need vitamin C(if one did I would have keeled over from scurvy years ago...) uric acid which your body produces on its own is an anti-oxidant that makes C look like the weak sickly distant cousin by comparison...