When you enter your vitamin as a food, you need to enter the number of milligrams. So for magnesium you would check the "info" link next to the nutrient (you can get there by clicking the CHANGE NUTRIENT GOALS link at the lower right hand side of the page). For magnesium you would see "Recommended daily intake: For men, 350 mg should be consumed daily, while women need 280 mg." So calculate 13% of that RDA for women and use that as your amount. After you have done that for all nutrients in your vitamin, click save. Now when you enter it in your food record it will add milligrams as with other foods.
Hope that helps. Let me know if you have any other questions I can help with.
6/8/13 9:08 P
I am fairly sure there's an explanation for this but there seems to be something strange that happens on the weekly tracker as it relates to keeping track of my vitamin requirements.
I want my multivitamin to be included in the weekly tracker, so I enter it as a food. Since the nutritional data is in % and not mg., I enter in that the vitamin provides 13% of the daily requirement of magnesium just as it says on the bottle (it is true with the other vitamins as well) and then when I look at the weekly tracker it shows that I have considerably less magnesium for my whole day than even the vitamin offers (since it provides the mg as well...)
So, I get 50 mg of magnesium in each tablet, but when I check the weekly tracker for today it says I got 23 mg. since that apparently is the 13%...