Zinc Nutrition During Pregnancy

Study Notes

Zinc is crucial for growth and development, with increased requirements during pregnancy.
A zinc-deficient diet hinders the mobilization of zinc stored in maternal skeletal muscle and bone, leading to a compromised zinc status.

Zinc is a part of 100 enzymes involved in the metabolism of macronutrients.
It provides a structural function in many tissues, including proteins involved in gene expression.

Zinc deficiency is highly teratogenic, leading to congenital malformations, such as anencephaly and oral clefts.
Mild zinc deficiency can result in impaired fetal growth and brain development, as well as impaired immune function.

Untreated low zinc levels associated with acrodermatitis enteropathica increase the risk of miscarriage, fetal growth restriction, hypertension, preeclampsia, preterm delivery, and intrapartum hemorrhage.

Zinc is widely available in red meat, seafood, whole grains, and some fortified breakfast cereals.
Extra supplementation beyond that found in prenatal vitamins is usually not required, but may be necessary for women with gastrointestinal disorders that affect absorption.

Overt zinc deficiency is rare in the United States, but rates are higher in areas where the main staple foods are high in phytates (e.g., unrefined cereals).
Vegetarian women may experience low zinc bioavailability due to high phytate intake.

Pica is a common condition during pregnancy, affecting 14% to 44% of women in the United States.
Common substances consumed during pica include dirt, clay, laundry starch, corn starch, ice, paper, burnt matches, stones, charcoal, bleach, cigarette ashes, baking soda, soap, tires, and coffee grounds.
Some substances are harmless, while others are dangerous to the mother's health.
The local poison control center can provide guidance on which substances require immediate intervention.

Pica is not limited to any geographic area, race, culture, or social status.
Cultural components influence the choice of substances and the acceptability of disclosure.
Preferred substances are often imported from home countries, including dirt, clay, and blocks of magnesium carbonate.

The cause of pica is poorly understood, but theories suggest it may relieve nausea and vomiting or be due to a deficiency of essential nutrients like iron, zinc, calcium, or potassium.
Pica may also be a craving for smell or texture as well as taste, and taste perceptions often change during pregnancy.

Malnutrition can occur when nonfood substances displace essential nutrients in the diet.
Consuming starch in excessive amounts can contribute to obesity and negatively affect glucose control.
Large intakes of baking soda can raise blood pressure, and extreme doses can cause rhabdomyolysis and cardiomyopathy.
Excessive intakes of baking powder can mimic preeclampsia.
Substances may contain toxic compounds or heavy metals, including lead, parasites, or other pathogens.
The absorption of iron or other minerals may be disrupted.
Excessive geophagia can result in intestinal obstruction or perforation.

Recommending cessation of pica often fails, so a more productive approach is to offer a better alternative.
Allowing the mother to continue to smell the substance but trading its consumption for a safer alternative can be successful.
Pica is often associated with iron deficiency anemia, and treatment with high iron foods may decrease cravings.