Just found out I'm anaemic and have been prescribed 400mg daily supplement. At first I was confused, I wouldn't say I feel any more fatigued than anyone caring for 2 very young dc who don't sleep through the night. However, I have been feeling very sluggish, and find it really hard to get up and crack on with stuff. Assuming this is the anaemia, how long before I suddenly have loads of energy and get up and go?