Selenium is an essential mineral and is abundant in a variety of different foods, and it's fairly easy for women to meet their daily selenium needs. Selenium is an antioxidant that helps prevent cell damage within the body -- and may prevent heart disease, certain cancers and may protect you against the toxic effects of heavy metals, notes "MedlinePlus." Getting plenty of selenium before a breast cancer diagnosis may improve your chance of survival, according to a study published in 2012 in "Breast Cancer Research and Treatment.
Adult women need at least 55 micrograms of selenium per day, which is the recommended dietary allowance, or RDA, that the Institute of Medicine has set. However, pregnant and nursing women require additional selenium to meet the needs of their developing babies. Selenium RDAs are 60 micrograms during pregnancy and 70 micrograms per day for breastfeeding women. Many women can meet these selenium needs by eating a well-balanced diet.
Selenium in Foods
In general, meat, seafood, dairy foods and nuts are excellent sources of dietary selenium. The Office of Dietary Supplements reports that Brazil nuts are especially rich in selenium, and contain about 544 micrograms per ounce. Chicken, fish, shrimp, ham, beef, turkey, cottage cheese, brown rice, oatmeal, eggs and baked beans also contain high amounts of dietary selenium, -- which is why selenium deficiency is rare in the U.S., notes the Office of Dietary Supplements.
Too Much Selenium
Although selenium deficiency is often uncommon in developed countries such as the U.S., consuming too much selenium is a concern -- especially if you’re taking a supplement that contains selenium or if you're eating lots of Brazil nuts on a regular basis. The Office of Dietary Supplements notes that consuming too much selenium can cause a metallic taste in your mouth or garlic-smelling breath, brittle hair and nails, fatigue, mottled teeth, irritability, lesions, diarrhea and nausea – and can eventually lead to hair loss, heart and kidney failure and even death. The tolerable upper intake level for selenium is 400 micrograms per day for all adults.
Selenium and Thyroid
Selenium plays a role in thyroid-hormone function, which helps a woman regulate her metabolism. A 2013 review published in “Clinical Endocrinology” reports that thyroid hormone contains high concentrations of selenium, and that although more research is necessary, selenium supplementation may play a key role in helping treat thyroid disorders. The Office of Dietary Supplements also notes that more research is needed to determine if selenium supplementation can treat or prevent thyroid disease.