TweetAccording to daily value percentage which is found on the box of most foods and supplements 5,000 IU is 100% of what you need in a day. However, someone on here mentioned that studies have shown that even minimal amounts over 100% (5,000 IU) of what you need in a day can be detrimental to your health. This info confuses me though; people who eat carrots would actually be taking a mega-dose since half a cup of carrots contains 19,152 IU of Vitamin A, yet I have not heard of people having health issues for eating carrots. So, how much Vit A is suitable to take in a day? I’m also asking because I recently bought GNC Mega man multivitamin/multimineral powder and the directions tell me to mix two tablespoons in my preferred drink. However, two scoops is equal to 5,000 IU of vit A, so I was thinking of only using one scoop to get 50% of the vit A, since I’m concerned about eating some other food later on that would add to the 100% that I already took in the supplement (if I were to use two scoops).