Calcium during pregnancy: too little, too much?

Calcium is arguably the most common nutrient known to (wo)man. The milk industry has etched its importance in the diet of Americans on the fact that the stuff is high in calcium. This obsession with calcium is inherently carried over to pregnancy. Just about every preggie gal wants to make sure she's getting enough in her diet despite the fact that prenatal supplements typically contain 300 mg. So it piqued my interest when a male family member commented on a valuable fact hidden at the bottom of table 2 on page 11 of my book: women during pregnancy should be getting 1,000 mg of calcium, the same amount as when they are not pregnant. My scritinizing uncle, baffled by this fact, asked me incredulously, "Is it really true that women don't need more calcium when they're pregnant?"

His skepticism is understandable. Babies in the womb need calcium for bone growth, so why wouldn't pregnant gals needs to consume more of the mineral? His logic seemed so sound that I had to double check the facts. it turns out that I somehow got it right: women during pregnancy and otherwise need to get 1,000 mg a day of calcium, according to the National Institutes of Health dietary guidelines for all vitamin and mineral intake in the United States. So at least I didn't mislead my readers.

"Yes, it does seem counter-intuitive," says Tara Gidus, a dietitian who is a spokeperson for the American Dietetic Association and the editor of my book. "I think what happens is that if you aren't eating enough [calcium during pregnancy], the fetus will take it from your body stores. Kidney stones comprised of calcium are common in pregnant women due to dehydration and also potentially from losing calcium from bones due to not getting enough in the diet."

"It's funny," she continued, "because if you google calcium needs in pregnant women, a lot of people report that women need 1200 mg (a 200 mg increase), but I'm not sure where they get it from.  I think one person wrote it once and then it gets regurgitated online."

So you're good to go if you're getting 1,000 mg a day - your body will take what it needs and give it to baby. But what if a preggie gals is overly focused on calcium and pounding 10 glasses of cow's milk a day - can she be getting too much?

It's possible. Turns out the upper tolerable limit for calcium is 2,500 mg a day calcium, and getting too much can lead to high calcium in the blood called hypercalcemia, high calcium in the urine called hypercalciuria and a host of other conditions.

As an aside, almonds, figs, oranges and bok choy are great great sources of calcium.