Vitamin B1 benefits, deficiency signs, dosages & food sources

Vitamin B1 benefits

Vitamin B1 (also known as thiamine), plays a big part in energy production from carbohydrates and fats. It is extremely important for the correct functioning of many different body functions such as the digestive and nervous system.

Along with vitamin C and other B vitamins, thiamine plays an important part in liver detoxification which can help with the clearing of many chemical and food sensitivities. Early symptoms of thiamine deficiency include muscle weakness, impaired memory and appetite.

According to researchers at the University of Maryland Medical Centre, the B-group vitamins, including vitamin B1, work together to support healthy skin, hair, live and eye function.

Vitamin B1 is often referred to as an 'anti-stress' vitamin, along with the other B-group vitamins.  

Do you experience any of the following on a regular basis or on a reoccurring basis?

Vitamin B1 deficiency signs

Abnormal eye movements

Anxiety and/or depression

Burning/hot feet



Loss of appetite

Muscle loss (atrophy)

Pins and needles or numbness

Poor circulation

Rapid heartbeat

Diabetes (type 2)

If you answered yes to 3 or more signs you could have a deficiency. Note not all symptoms will be present in the one person. As with all health questionnaire results, also check with your doctor to rule our more serious health problems. 

Vitamin B1 deficiency can also result in a disease called Beri Beri, which includes symptoms such as emotional disturbances, swelling, pain and weakness of the limbs, weight loss, vomiting, swelling of lower legs and irregular heartbeat. 

Vitamin B1 dosages and food sources

Vitamin B1 

Supplement dosages (milligrams per day)

Eczema-friendly food sources

Also known as:



Infants (AI)

0.2-0.3 mg from breast milk or hypoallergenic (dairy-free) infant formula

Children (RDI)

1–4 years: 0.4–0.5 mg

5–12 years: 0.6–0.9 mg

13–18 years: 1.1–1.2mg

Adults (RDI)

1.1 to 1.2 mg

1 cup navy beans: 0.43mg

1 cup black beans: 0.42mg

1 cup lentils: 0.33mg

¼ cup (2oz) oats: 0.33mg

2 tablespoons flaxseeds: 0.23mg^

1 cup (8oz) sweet potato: 0.21mg^

1 cup (8oz) Brussels sprouts: 0.17mg

1 cup cabbage: 0.11mg

1 scoop Skin Friend AM: 0.67mg (child dose)

2-3 scoops Skin Friend AM: 1.35mg- 2mg (teen and adult dose)

AI = Adequate Intake as per Australian Government guidelines

RDI – Recommended Daily Intake as per Australian Government guidelines – shown on the table as the lowest dose. The higher range covers the therapeutic range.

^Contains salicylates (not suitable during weeks 1–3 of the FID Program)

Vitamin B1 food sources eczema diet image

Important notes about B-group vitamins

When taking any kind of B vitamins keep the following nutrition rules in mind:

  • As B-group vitamins are acidic, avoid mega-doses above 15 mg, especially if you have eczema.
  • In order to prevent deficiencies of other B vitamins, take vitamin B1 in supplement form along with other B vitamins, not as a single supplement.

Authors: Layland, K. and Fischer, K., 2017 'Vitamin B1 benefits, deficiency signs, dosages & food sources', Eczema Life Clinic.

Supporting research

D'Amour, M.L., Bruneau, J. and Butterworth, R.F., 1991. Abnormalities of peripheral nerve conduction in relation to thiamine status in alcoholic patients. Canadian Journal of Neurological Sciences/Journal Canadien des Sciences Neurologiques, 18(02), pp.126-128.

Rabbani, N. and Thornalley, P.J., 2011. Emerging role of thiamine therapy for prevention and treatment of early‐stage diabetic nephropathy. Diabetes, Obesity and Metabolism, 13(7), pp.577-583.

Stanton, R, 2007, Vitamins, 'Rosemary Stanton’s Complete Book of Food and Nutrition', pp 470-471.

Costantini A, Pala MI. Thiamine and fatigue in inflammatory bowel diseases: an open-label pilot study. J Altern Complement Med. 2013;19(8):704-8.

University of Maryland Medical Centre, 2015, Vitamin B1 (Thiamine) retrieved from

Photos by Karen Fischer: lentils, oats and black beans (plate by Made of Australia); and the drink is Skin Friend AM mixed into water.