Did you know that your body will absorb vitamins differently depending on what time you take them? If you don't take vitamins consistently, you many not be getting optimal levels during the week. Fat-soluble vitamins, such as A, D, E and K, are best taken with foods containing fat, such as avocados and almonds. Vitamin B is best taken at breakfast, as it can be too stimulating for nighttime. Iron and magnesium can upset an empty stomach, so they are best taken at dinner. Some vitamins work well together, such as vitamin D and magnesium, which help your body absorb calcium. Vitamin B12 and vitamin C help the body process folic acid.