Selenium

Why do you need it?

Selenium is an antioxidant – it protects your cell membranes and DNA from damage linked to heart disease, cancer and other diseases. It helps your thyroid gland work normally and plays a role in fertility by helping protect ovaries and sperm from free radical damage.

It’s naturally found in the soil, but because levels vary, the selenium content of plant foods varies too.

There’s no benefit from taking extra selenium and high intakes can cause hair and nail loss or brittleness, skin rashes, nausea, irritability, tiredness and even mild nerve damage. The safe maximum intake is 450 micrograms a day.

Deficiency

Symptoms of deficiency include hair loss, fingernail discoloration, low immunity, tiredness, difficulty concentrating, reproductive problems, hypothyroidism (low function of the thyroid); extreme deficiency can lead to Keshan disease (cardiomyopathy) or Kashin-Beck disease (a type of osteoarthritis).

How much do you need?

The World Health Organisation (WHO) recommends 26 micrograms (μg) of selenium a day for women aged 19 and over and 34 micrograms (μg) of selenium a day for men aged 19 and over. The recommended intakes for infants, children, adolescents and pregnant and lactating women are given below.

Recommended nutrient intakes for selenium. Click to read more…
Age groupRecommended nutrient intake μg/day
Infants and children
0-6 months6
7-12 months10
1-3 years17
4-6 years22
7-9 years21
Adolescents
Females, 10-18 years26
Males, 10-18 years32
Adults
Females, 19-6525
Females, 65+25
Males, 19-6534
Males, 65+33
Pregnant women
2nd trimester28
3rd trimester30
Lactating women
0-6 months35
7-12 months42
Source: WHO, FAO. 2004. Vitamin and mineral requirements in human nutrition. 2nd ed. Geneva: WHO.

Where to find selenium

Selenium levels in plant foods vary widely depending on soil conditions etc. Therefore, it’s important to eat a varied diet, rich in a wide mix of fruit, vegetables, wholegrains, pulses, nuts and seeds. The best plant sources of selenium include Brazil nuts, sunflower and sesame (simsim) seeds, wholegrains, tofu, asparagus and mushrooms.

  • Brazil nuts: Brazil nuts are one of the richest plant-based sources of selenium. They can be found in Uganda, although they may not be as commonly consumed as in other regions. The amount contained in a small handful (28 grams) of Brazil nuts can range from 24 to 193 micrograms. Eating just one or two Brazil nuts each day can provide a significant amount of selenium.
  • Sunflower and sesame seeds: Both types of seeds are a good source of selenium. They can be consumed as a snack or added to salads, desserts or smoothies. A quarter cup (35 grams) of sunflower seeds provides almost 19 micrograms of selenium.
  • Pulses: Peas, beans and lentils contain moderate amounts of selenium and are commonly eaten in Uganda and can be included in various dishes like soups, stews and salads. One cup (198 grams) of cooked lentils contains around six micrograms of selenium. 
  • Wholegrains: Brown rice and millet contain moderate amounts of selenium but are a staple food that can contribute to your daily intake. A cup (202 grams) of cooked brown rice contains 12 micrograms of selenium. 
  • Mushrooms: Some mushrooms contain selenium and can contribute to dietary intake. A 100-gram serving of button mushrooms provides 20 micrograms of selenium.