Lean and fat fish both contain selenium. Other sources are offal, fish and grain products.
Why is selenium important?
Selenium is incorporated into more than 20 selenoproteins, which play an important role in reproduction, the metabolism of thyroid hormones, DNA synhthesis and in antioxidant defence mechanisms. Selenium also plays an important role in the detoxification reactions of various heavy metals. Selenium can play a role in connection with cardiovascular disease, cancer and mental health. We have 5-15 milligrams of selenium in our bodies, distributed between all of our cells and tissue, though most in the liver and kidneys.
Lack of selenium
How much selenium we need has not been fully ascertained, and we know little about the symptoms of selenium deficiency.
The recommended daily intake of selenium is 50 micrograms for men and 40 micrograms for women. Pregnant and breastfeeding women should have an intake of 55 micrograms per day. The elderly may need more selenium because the natural immune system deteriorates with age. The upper daily intake limit is set at 300 micrograms of selenium. Too much selenium can cause nausea, vomiting, hair loss and damage to nails.
Status in the population
The selenium status is measured as serum in the blood and in the red blood cells.
Most people get enough selenium by eating a varied diet. The daily dietary intake is assumed to be 70-80 micrograms.