I bought these vitamins when I was going through a major nutritional deficiency stage (sometimes I get very low on things, especially iron) and I needed to boost my vitamin/mineral levels quickly because of the side effects I was having (dizziness, lightheadedness, disorientation, etc). I took these for a few days and they hurt my stomach so badly. Every time I took them, I ended up with a massive stomach ache so I stopped taking them. I'm not sure what it was, I was taking them with meals as directed on the bottle. So these probably aren't suitable for everyone.