Selenium is an essential trace mineral. It is naturally present in various foods and is available as a dietary supplement. This mineral also supports immune system function and thyroid hormone metabolism.
Selenium’s Role in Pregnancy
Selenium plays a significant role in maintaining health during pregnancy for both the mother and the developing fetus. It is a component of selenoproteins, which provide antioxidant defense. These selenoproteins help protect against oxidative stress, a process that can damage cells and tissues, particularly relevant during gestation due to increased metabolic demands.
The mineral also contributes to proper thyroid hormone metabolism. Inadequate maternal selenium levels can affect fetal thyroid development and hormone production. Selenium also supports immune function. Research suggests that appropriate selenium levels may help reduce the risk of certain pregnancy complications, such as pre-eclampsia, gestational diabetes, and preterm birth.
Getting Enough Selenium
The recommended daily allowance (RDA) for selenium in pregnant individuals is 60 micrograms (mcg) per day. This amount increases to 70 mcg daily for those who are breastfeeding.
Various foods are rich in selenium, including Brazil nuts, which are exceptionally high in this mineral, providing around 544 mcg per ounce (approximately six to eight nuts). Other sources include seafood like yellowfin tuna, sardines, shrimp, cod, and salmon. Lean meats such as chicken, beef, pork, and turkey also contain selenium, along with eggs, dairy products like cottage cheese, and whole grains. The selenium content in plant-based foods can vary significantly depending on the selenium levels present in the soil where they are grown.
Consequences of Imbalance
Both insufficient and excessive selenium intake during pregnancy can lead to health concerns for the mother and baby. Selenium deficiency can increase the risk of complications such as pre-eclampsia, gestational diabetes, and fetal growth restriction. It can also impact immune function and thyroid health in the mother.
Excessive selenium intake, known as selenosis, can also cause health issues. Symptoms of selenosis may include hair loss, brittle nails, gastrointestinal issues, skin rashes, and a garlic-like odor on the breath. In severe cases, it can lead to neurological problems and extreme fatigue. The Tolerable Upper Intake Level (UL) for selenium for pregnant individuals is 400 mcg daily, encompassing intake from all sources including food, beverages, and supplements.
Supplementation Considerations
Selenium supplementation might be considered for pregnant individuals in areas with low soil selenium levels or for those with specific dietary restrictions that limit their intake of selenium-rich foods. However, it is important to exercise caution with supplementation due to the narrow range between beneficial and potentially harmful doses. Many prenatal vitamins already contain some selenium, so checking the label of any current supplements is advised. Before initiating any selenium supplement, it is important to consult with a healthcare provider. They can assess individual needs, recommend an appropriate dosage if necessary, and help ensure that supplementation is safe and does not lead to excessive intake.