Calcium and Pregnancy

The efficiency of calcium absorption in pregnant women is approximately double that of non-pregnant women. These changes are seen from as early as the 12th week of pregnancy. During her pregnancy, the woman’s body will increase the rate at which intestinal calcium absorption takes place. The baby’s demand for calcium will increase during pregnancy from around 50mg/day at 20 weeks gestation to 330mg/day at 35 weeks.

There have not been many scientific studies performed on the impact that this foetal demand has on the pregnant mums’ bone density as the most sensitive testing machinery uses radiation technology, the exposure to which is not recommended during pregnancy.

The conclusion reached in a study presented in The American Society for Nutritional Sciences is that “the bone response to pregnancy appears to differ between individual women” and that “changes in bone mineral content may be governed by a variety of influences, such as the mother’s age or parity and endocrinological status before or after conception” and that “nutritional status may also be influential”.

In contrast, a number of studies have shown evidence that lactation is associated with significant reductions in maternal bone mineral content. These bone changes are highly variable and some women can experience decreases in the bone mineral content at the spine of up to 10%. However, after breastfeeding has stopped, evidence shows that with the correct nutrient intake, the body will restore the bone mass to its pre-pregnancy levels.

A warning that did come out of the study, however, is that “the mobilisation of bone to support pregnancy and lactation could, if excessive or if insufficiently restored, increase the risk of osteoporotic fractures both during reproduction and in later life”.