What I learned in my college Nutrition class...

I learned that taking vitamin supplements is really not that good. If you don't eat much and must take them go ahead but many vitamins have too much in them and it's an overload for your body to try and get rid of. I learned that iron is hard for the body to excrete once it's in your system so be careful with it. Iron from caste iron pots is not absorbable and carcinogenic. Some vitamins need precursors/helpers like B12, Vit. D and some others, I'll go back to my book and post you on it. The B12 in spirulina the body can't absorb and spirulina can be toxic. (No wonder I was personally having many problems with spirulina).
I also learned that taking more than 200mg of Vitamin C a day can be detrimental. The tissue saturation level does not go up with high doses of vitamin C and the body starts to excrete it in your urine. Too much vitamin C can be a pro-oxidant which is the flip side of antioxidant. It can exacerbate kidney stones and cause what they say is free iron to run rampant in your system which become free radicals which aren't good. Now I'm just going by my class and book. Please don't come on here and bash me. I just thought I would share.
It's best to get all your vitamins and minerals from whole foods. Do vitamin supplements minimally if at all. And yes milk is good for you. A woman of childbearing years still need calcium, Folic acid, Vitamin D (sunshine), phosphorus etc and you get that from milk. Anyone have any questions for me and I'll look into it for you.