“During pregnancy, we focus on calcium both as a nutrient necessary for your baby’s development and for maintaining healthy bones across mom’s lifetime.”–Dr. Lisa Watson, ND

Calcium is classified as an “essential” nutrient because our bodies cannot manufacture its own calcium. Calcium is not just a recommended nutrient during pregnancy, it is critical to both the mother’s health and the baby’s health. 

Although calcium is generally important in daily nutrition, most of us do not take in enough calcium in our diet. In fact, did you know that as many as 68% of women are calcium deficient? Calcium deficiency in daily life affects many women, but during gestation, it is important to know that calcium plays an even bigger role.


Calcium is essential for strong bones, teeth, muscle and heart. This means that in those nine months, calcium helps to build the baby’s bones, teeth, nerves and muscles; it also helps in blood-clotting abilities.

If the mother isn’t getting enough calcium, her body will draw the necessary calcium for the baby from her bones and teeth. If enough bone mass is lost, the mother is at risk for osteoporosis later down the road. Besides being an important nutrient in bone health, calcium helps our blood to clot. You might not know it but calcium also plays an important role in our nerves and muscle contractions. At its worst, calcium deficiency can cause seizures.

Low calcium intake will affect the baby’s skeletal growth. While low calcium in breast milk affects the baby’s development after birth. As mentioned, one of the dangerous outcomes of a calcium deficiency during a pregnancy is that the fetus might come to draw calcium from the mother’s bones, causing a health risk to the mother. Weak bones and joints can also lead to long-term conditions like rheumatoid arthritis and osteoporosis.

Side Effects/Risks

However, as usual, be careful not to overdo it. Too much calcium can cause constipation, irritability and changes to your appetite. More importantly, it may affect your body’s absorption of iron and zinc (two essential nutrients during pregnancy). If prolonged, overly high intake of calcium can even lead to kidney stones.

Moreover, if you are taking a supplement, do read the ingredients. Avoid supplements with ingredients that may contain lead (such as oyster shell, dolomite and coral).

Also remember that you do need Vitamin D in order to absorb calcium effectively! Most calcium supplements are also fortified with Vitamin D.

If you are taking over-the-counter or prescription medication, talk to your doctor about possible interactions between calcium supplements and those medications.


During gestation, calcium is at a high demand.  The baby alone needs about 50mg per day by the second trimester and 250mg per day in the third trimester.

No more than 2500 mg of calcium is recommended per day. The ideal dose of calcium is around 1000 mg a day. Many prenatal vitamins however contain less than the recommended daily dosage of calcium so be alert and supplement vitamins with other natural sources of calcium.

Food Sources for Calcium

  1. Spinach
  2. Kale
  3. Broccoli
  4. Collards
  5. Okra
  6. Bok choy
  7. Fish like sardines and salmon are especially great as they also contain Vitamin D
  8. Dairy products
  9. Legumes
  10. Almonds
  11. Soybean