By

A member of the British Dietetic Association, Juliette Kellow has worked in the NHS and for the food industry, and is the former editor of magazines Slimming and Top Santé. She's also the former editorial...


What happens if I don’t get enough vitamin B1?
A full-blown deficiency in the western world is rare. Indeed, vitamin B1 is one of the few foods that most groups of people in the UK get more than enough of – figures show that men have an average of 1.59mg a day and women, 1.28mg. The exceptions are people who suffer with alcoholism.

Alcohol has many negative effects on vitamin B1 levels in the body. For example, it reduces vitamin B1 absorption from the gut, and lowers the uptake and use of B1 in the body’s cells. Early signs of a deficiency include nausea, cramps, muscle fatigue, depression, irritability and poor co-ordination.

The main sources of vitamin B1
Many foods contain vitamin B1, which is why it’s easy for most people to get enough each day. The main sources are wholegrain cereals (especially bread), fortified breakfast cereals, oats and brown rice. Other B1-rich foods include pulses, seeds, nuts, red meat (especially pork and pork products), fish and offal.

Everyday foods for vitamin B1

Everyday foods for vitamin B1

Drinking danger
Many foods contain vitamin B1, which is why it’s easy for most people to get enough each day. The main sources are wholegrain cereals (especially bread), fortified breakfast cereals, oats and brown rice. Other B1-rich foods include pulses, seeds, nuts, red meat (especially pork and pork products), fish and offal.

How much vitamin B1 do I need each day?
The Nutrient Reference Value (NRV) for vitamin B1, which you’ll see on food labels, is 1.1mg. But there are more detailed guidelines in the UK for vitamin B1 needs at specific ages and stages in life:

how much vitamin b1 do i need

PMS connection to vitamin B1
A recent study suggested vitamin B1 supplements help to ease the symptoms of PMS. More research is needed, but it may be worth making sure you have good intakes if you suffer with PMS.

Diabetes debate about vitamin B1
Research is increasingly showing a link between vitamin B1 deficiency and type 2 diabetes, although more studies are needed to confirm why this is.

How to retain the vitamin B1 in food

  • As it’s a water soluble vitamin, it’s sensitive to heat, so cooking can deplete levels in food. Steam rather than boil B1-rich vegetables to retain as much of the vitamin as possible.
  • The longer food is cooked, the more vitamin B1 tends to be destroyed. Scrambled eggs lose about 5% of their vitamin B1, but baked eggs lose 15%.
  • Processing also affects it, which is why wholegrain products tend to contain far more vitamin B1 than the corresponding white products (it’s the outer layers of the grain that contain most). Long-grain rice contains no vitamin B1, whereas a 150g portion of cooked brown rice provides 15% of our daily need for this nutrient. White pasta twists contain minimal B1, but 200g wholewheat pasta gives us a fifth of the recommended daily intake.

Related article: Why we need vitamin B2