Iron vs. Calcium

Yesterday in class we talked about iron and calcium, and how the two nutrients interact. Sometimes we are so focused on getting all of our nutrients – whether it be from three meals or from a multivitamin – that we forget about the effect that certain nutrients have on one another and on our ability to absorb and utilize them.

It is important to understand the relationship between iron and calcium. Iron actually blocks the absorption of some minerals, especially calcium. So, if you’re taking a daily multivitamin with both iron and calcium, you are probably not really getting the full calcium amount listed on the bottle.

In addition to iron blocking calcium absorption, too much calcium can interfere with iron absorption. Other things that can inhibit iron absorption include tea, coffee, wheat bran, egg yolks, and even antacids. Vitamin C, on the other hand, actually enhances iron absorption.

If you are iron deficient, I recommend taking your iron supplement at a different time of day than when you take your multivitamin. And if you are worried about having enough calcium, you may want to take a separate calcium supplement, or find a multivitamin that contains calcium but no iron. Iron can also interfere with magnesium and zinc absorption, which is something to keep in mind.

I guess the lesson here is that we cannot just buy a multivitamin and expect it to correct all of our nutrient deficiencies. Supplementing with vitamins can be really beneficial, but it is so important to eat a varied diet as well to ensure we are getting everything we need.

We also touched on pregnancy and the importance of the mother getting enough calcium, especially during the 2nd trimester when the baby's bones are becoming ossified. Even though calcium is found in the prenatal vitamins that most pregnant mothers take, they may not be absorbing all of it. Some doctors or naturopaths recommend they actually take a separate calcium & magnesium supplement during the 2nd trimester, to ensure they have enough. The baby needs that calcium no matter what, so the person who ends up suffering from a deficiency is the mother, in the form of leg cramps, twitches, muscle aches, and even tooth decay.

Some great whole food sources of iron include soybeans, lentils, spinach, sesame seeds, kidney beans, raw pumpkin seeds, garbanzo beans, blackstrap molasses, and lean beef.