Supplemental potassium is not needed during normal, healthy pregnancies beyond what is recommended for all adults.
However – vomiting can cause potassium loss, and vomiting is common during the first trimester. Severe vomiting, where electrolytes cannot be quickly replaced (in a 24-hour period) may become serious.
These consequences can come on quicker with a bad case of food poisoning or stomach virus during pregnancy in which diarrhea is also a symptom. Low potassium (hypokalemia) can also occur through excessive sweating on top of over-hydration during exercise or heat exposure.
Severe potassium loss during pregnancy is rare, but if women experience intense or prolonged gastrointestinal illness during pregnancy, a trip to the hospital may be required for intravenous (IV) therapy to replenish electrolytes.
Excess potassium is not usually a concern during pregnancy, but conditions such as diabetes or certain medications can increase a woman's risk for hypokalemia (high potassium).
Women should be aware of risk factors, as well as the signs and symptoms of potassium deficiency and excess described below, and should call their health care provider (HCP) if they have any concerns.
Background
When levels of potassium in the body are low in any individual, the body has difficulty functioning. Hypokalemia (low potassium) can be caused by:
Pregnancy
The fetus accumulates potassium throughout pregnancy, but very little is known about potassium’s effects on pregnancy, or if potassium requirements change.
However, effects of too little potassium are well known and can cause severe consequences during pregnancy, especially if a pregnant woman suffers from severe, and prolonged vomiting (and/or diarrhea) at any point. Hypokalemia is not uncommon in women with hyperemesis gravidarum.
Potassium can be quickly lost through vomiting. Symptoms of early hypokalemia include fatigue, abdominal pain, cramps, constipation, and muscle weakness. Severe hypokalemia is life threatening; it can cause increased urination, decreased brain function, high blood sugar levels, muscle paralysis, difficulty breathing, and irregular heartbeat that can be fatal.
Treatment for severe low potassium is oral or intravenous potassium in a hospital setting. Heart rate monitoring is also necessary before and during treatment.
It is recommended that pregnant women with severe vomiting and/or diarrhea, or who cannot keep fluids down for 12 to 24 hours should call their HCP or seek emergency care if severe. HCPs will request blood work to make sure potassium levels are safe.
Hyperkalemia (high potassium) is not usually a concern during pregnancy but is associated with a higher risk for gestational diabetes and severe preeclampsia, and could indicate kidney problems.
High potassium levels can be caused by ACE inhibitors and certain diuretics that are used to treat high blood pressure, edema, and congestive heart failure; type 1 diabetes can also cause hyperkalemia.
Symptoms of hyperkalemia may include tingling of the hands and feet, muscular weakness, and temporary paralysis. The most serious complication of hyperkalemia is the development of an abnormal heart rhythm (cardiac arrhythmia) which can lead to cardiac arrest.
HCPs will likely monitor women who may be at risk for either hypokalemia or hyperkalemia.
Supplementation
It is recommended that pregnant women consume about 2,900 milligrams (mg)/day of potassium; an upper limit has not been set as toxic effects from too much dietary potassium has not been reported.
Potassium is found in many multivitamin supplements, however, most only contain about 99 mg/day.
If potassium is lost through vomiting or excessive sweating, potassium should be replaced through foods or sports drinks rather than through supplements when possible.
Supplemental potassium during pregnancy is not recommended unless specifically directed by an HCP.
Side effects of potassium supplements can include nausea, vomiting, abdominal discomfort, and diarrhea, which can be confusing when supplementation is required. The best method during pregnancy/illness is replacement of potassium through food/drinks under the observation of an HCP.
Food Section
Potassium is found in a variety of foods such as bananas, dried apricots, raisins, orange juice, acorn squash, potatoes, spinach, tomatoes, broccoli, zucchini, eggplant, pumpkin, carrots, cantaloupe, quinoa, soybeans, nuts, milk, yogurt, meats, poultry, fish, and almonds.
Action
Women who are concerned about their potassium status during pregnancy should speak to their HCP, especially if they are experiencing severe nausea and vomiting of pregnancy, have been diagnosed with diabetes, or take medications to control blood pressure.
Partner/Support
For women suffering with severe nausea and vomiting of pregnancy, or even a bout of food poisoning or stomach virus, potassium loss can occur quickly depending on the severity of symptoms. When women are very ill, it can sometimes be difficult for them to indicate if they may need help.
Partners should be aware of the signs/symptoms described above, check on the woman often when she is ill (i.e. vomiting), and call her HCP if she cannot keep fluids down for 12 to 24 hours. Women with severe dehydration (signs/symptoms here) may require a trip to an emergency department.
Resources
Potassium (U.S. National Institutes of Health)