Milk helps you meet the recommended daily intake for vitamins A and D, calcium, potassium, and phosphorus. On the other hand, you want to steer away from taking your multivitamins with a glass of milk. The reason is because it might limit the amount of calcium and iron you absorb from your multivitamins. A better alternative would be having a glass of orange juice because the vitamin C it contains improves iron absorption.
Having more than 500 milligrams of calcium at one time, doesn’t allow your body to absorb as much calcium. Therefore, if you combine multivitamins with milk, it could cause you to go over this amount. To put it into perspective, an 8-ounce glass of 2 percent milk has about 293 milligrams of calcium and many multivitamins contain more than 200 milligrams of calcium. Taking your multivitamins with milk could also reduce the absorption of iron from your multivitamins. Consuming 165 milligrams or more of calcium along with iron can decrease iron absorption by as much as 60 percent, according to a study published in the “American Journal of Clinical Nutrition” in January 1991. To avoid this interaction, take your multivitamins at least two hours before or after consuming any dairy products, recommends MedlinePlus.