Vitamin B1 – thiamine

Why do you need it?

The B vitamins help release energy from your food, so, missing out on them can affect your energy levels. B vitamins also help how your body handles fat and protein. We need them for a healthy immune system and maintaining our nervous system which transmits signals between the brain and the rest of your body. Your nervous system controls your ability to move, breathe, see, think and more, so it is very important. 

Like all the B vitamins, thiamine is water-soluble. Although we store a small amount of thiamine in our liver, heart, kidney and brain, we don’t build up large stores of this vitamin, so you need it in your diet every day. 


In many high‐income countries, wheat flour and cereals are fortified with thiamine and in these countries, fortified foods contribute about half of the total vitamin intake. In low- and middle-income countries, thiamine fortification is less common and not having a varied diet or relying on staple foods lacking in thiamine is a leading cause of deficiency.

Symptoms of mild to moderate deficiency include weight loss, confusion, memory loss, muscle weakness, numbness and tingling in the feet or hands and lowered immunity. Severe malnutrition and lack of thiamine can lead to a disease called beriberi, characterised by swelling, tingling, or burning sensation in the hands and feet, confusion and lack of mental awareness, trouble breathing (because of fluid in the lungs) and uncontrolled eye movements (nystagmus). Beriberi is not common in Uganda but can be seen in communities with limited access to a varied diet, for example, among those whose diet is based mainly on cassava and/or white rice.

How much do you need?

The World Health Organisation (WHO) recommends 1.1 milligrams of thiamine (vitamin B1) a day for women and 1.2 milligrams a day for men. The recommended intakes for infants, children and adolescents, as well as pregnant and lactating women are given below.

Recommended nutrient intakes for thiamine. Click to read more…
Age groupRecommended nutrient intake mg/day
Infants and children
0-6 months0.2
7-12 months0.3
1-3 years0.5
4-6 years0.6
7-9 years0.9
Females 10-18 years1.1
Males 10-18 years1.2
Females, 19-65 years1.1
Males, 19-65 years1.2
Pregnant women1.4
Lactating women1.5
Source: WHO, FAO. 2004. Vitamin and mineral requirements in human nutrition. 2nd ed. Geneva: WHO.

Where to find vitamin B1 (thiamine)

The best plant sources of thiamine are wholegrain foods, pulses, nuts, seeds and some fruit and vegetables. Ugandan staples including white rice, cassava, potatoes and plantain contain low levels of thiamine and can’t be relied on to meet your needs

  • Wholegrain foods: Brown rice, millet and sorghum are popular foods in Uganda and can provide a significant amount of thiamine in the diet. Processing foods reduces their thiamine levels, for example, brown rice contains ten times the amount of thiamine found in white rice – choose the wholegrain varieties.
  • Pulses: Popular varieties include yellow, green and split peas, red kidney beans, black beans, mung beans, cowpeas (black-eyed peas) and red ‘masoor’ lentils. They are a versatile staple in Uganda and are used in curries, soups, stews, salads or simply boiled and served as a side dish. They can provide a significant amount of thiamine in your diet. One cup (172 grams) of boiled black beans can provide 0.42 milligrams of thiamine.
  • Nuts and seeds: Peanuts, sunflower and sesame (simsim) seeds are also good sources of thiamine.  
  • Green leafy vegetables: Spinach, kale and amaranth leaves may provide a significant amount of thiamine in the diet. One cup (180 grams) of cooked spinach contains 0.17 milligrams of thiamine. Because thiamine dissolves in water, a significant amount of the vitamin is lost when cooking water is thrown out. Steam vegetables instead of boiling them or cook in less water and let the food absorb it.  
  • Fruits: Some fruit such as oranges and guavas are good sources of thiamine. One orange (151 grams) contains 0.15 milligrams of thiamine.