Vitamin B1 (Thiamin) Beach Body Guide

Vitamin B1 (Thiamin or Thiamine) plays a central role in the generation of energy from carbohydrates, working with other B-group vitamins to help break down and release energy from food. It also assists with keeping nerves and muscle tissue healthy.

Thiamin pyrophosphate (TPP), the active form of thiamin, is involved in several enzyme functions associated with the metabolism of carbohydrates, branched-chain amino acids, and fatty acids.

Vitamin B1 Deficiency (beriberi)

Low levels of thiamine in the body, known as beriberi, can cause inflammation of the nerves (neuritis), digestive problems, ulcerative colitis and diarrhea. It is often associated with alcoholism.

Thiamine supplementation is often recommended for AIDS, boosting the immune system, diabetic pain, heart disease, alcoholism, aging, cerebellar syndrome, canker sores, cataracts, glaucoma, motion sickness, and improving athletic performance.

Other uses include preventing cervical cancer and progression of kidney disease in patients with type 2 diabetes.

Vitamin B1 and the Brain

Thiamin plays an active role in the brain, and some people use thiamine for maintaining a positive mental attitude; enhancing learning abilities; increasing energy; fighting stress; preventing memory loss, Alzheimer’s disease and stuttering.

Healthcare providers give thiamine shots for a memory disorder called Wernicke’s encephalopathy syndrome, alcohol withdrawal, and comas.

Vitamin B1 Toxicity

There are no known toxic levels of Thiamine, thus there is no defined upper limit of intake. Vitamin B1 is only marginally stored in our body and excessive amounts are easily excreted in the urine.

However, drowsiness or hypersensitivity to Thiamine is possible but rare. One study giving up to 8g per day for a year to Alzheimer’s patients found no side effects, except for nausea and indigestion in two subjects when they reached 7000 and 7500 mg per day[1].

Thiamin with Tea and Coffee Extracts

Chemicals in coffee and tea called tannins can react with thiamine, converting it to a form that is difficult for the body to take in. This could lead to thiamine deficiency.

Interestingly, thiamine deficiency has been found in a group of people in rural Thailand who drink large amounts of tea (>1 liter per day) or chew fermented tea leaves long-term. However, this effect hasn’t been found in Western populations, despite regular tea use. Researchers think the interaction between coffee and tea and thiamine may not be important unless the diet is low in thiamine or vitamin C. Vitamin C seems to prevent the interaction between thiamine and the tannins in coffee and tea.

If you are taking large quantities of green tea or coffee extract for fat loss, such as with Tim Ferriss’s PAGG stack,  it might be worth considering supplementing your B vitamins (as Tim suggests).

Recommended Daily Intakes

  • The Daily Value (DV) set by the FDA for vitamin B1 is 1.5 mg for adults.
  • The Institute of Medicine recommends an RDA (Recommended Dietary Allowance) of 1.2mg for men and 1.1mg for women.
  • In the UK, the RDA (Recommended Daily Allowance) is 1 mg for men and 0.8 mg for women.

Research suggests that there is a direct correlation between the number of Calories consumed and the amount of vitamin B1 needed to metabolise the energy properly [3].

Judged from the results of this study, the recommended intake for the adult human of 0.40 mg of thiamin per 1000 kcal by FAO/WHO and the recommended allowance of 0.5 mg per 1000 kcal by the Food and Nutrition Board of the NAS-NRC appear reasonable and amply allow for biological variations and other factors that may influence the requirement for this vitamin.

Getting Thiamin from Food

Lots of food contains vitamin B1, albeit in smallish quantities. Generally speaking, you can meet the recommended amounts jut by eating a healthy diet.

FoodServing sizeThiamin (mg)
Vegetables and Fruit
Soybean sprouts, cooked125 mL (1/2 cup)0.28
Edamame/baby soybeans, cooked125 mL (1/2 cup)0.25
Green peas,  cooked125 mL (1/2 cup)0.22 – 0.24
Lima beans, cooked125 mL (1/2 cup)0.22
Squash, acorn, cooked125 mL (1/2 cup)0.18
Potato, with skin, cooked1 medium0.10-0.15
Grain Products
Wheat germ, raw30 g (¼ cup)0.50
Corn flour20 g (2 Tbsp)0.29
Pasta, white, enriched, cooked125 mL (1/2 cup)0.21- 0.29
Pasta, egg noodles, enriched, cooked125 mL (1/2 cup)0.16 – 0.21
Oatmeal, instant, cooked175 mL (¾ cup)0.72-1.10
Cereal, dry, all types30 g (check product label for serving size)0.60
Hot oat bran cereal, cooked175 mL (¾ cup)0.40
Muesli and granola30 g (check product label for serving size)0.22 – 0.30
Oatmeal (1 minute), cooked175 mL (¾ cup)0.21
Other Grain Products
Breakfast bar, corn flake crust with fruit1 bar (37 g)0.37
Bagel, plain½ bagel0.27
Breakfast bar, oatmeal1 bar (47 g)0.24
Granola bar, oat, fruits and nut1 bar (43 g)0.21
Waffle, frozen, cooked1 waffle0.19
Bread (white, whole wheat, rye, mixed grain)1 slice (35 g)0.10 – 0.17
Milk and Alternatives
Soy beverage,250 mL (1 cup)0.16
Meat and Alternatives
Pork, various cuts, cooked75 g (2 ½ oz)0.36- 1.05
Pork, ground, cooked75 g (2 ½ oz)0.75-0.77
Pork, ham, cooked75 g (2 ½ oz)0.41
Venison/deer, various cuts, cooked75 g (2 ½ oz)0.19 – 0.38
Liver (chicken, pork), cooked75 g (2 ½ oz)0.13-0.22
Fish and Seafood
Tuna,yellowfin/albacore, cooked75 g (2 ½ oz)0.38
Trout, cooked75 g (2 ½ oz)0.11-0.32
Salmon, Atlantic, cooked75 g (2 ½ oz)0.21 – 0.26
Pickerel/walleye, cooked75 g (2 ½ oz)0.23
Mussels, cooked75 g (2 ½ oz)0.23
Tuna, bluefin, cooked75 g (2 ½ oz)0.21
Meat Alternatives
Meatless, luncheon slices75 g (2 ½ oz)3.00
Soy burger, vegetarian meatloaf or patty, cooked75 g (2 ½ oz)2.00
Meatless (chicken, fish sticks, meatballs), cooked75 g (2 ½ oz)0.70-0.96
Legumes (dried beans, peas and lentils)
Beans (soybeans, black, pinto, adzuki, kidney, lima, navy, roman), cooked175 mL (¾ cup)0.18 – 0.32
Lentils, cooked175 mL (¾ cup)0.25-0.28
Baked beans, canned175 mL (¾ cup)0.18
Nuts and Seeds
Sunflower seeds, without shell60 mL (¼ cup)0.54
Chinese/Japanese chestnuts,  without shell60 mL (¼ cup)0.16 – 0.32
Nuts (pistachio, macadamia, brazil nuts, hazelnuts, pecans, peanuts), without shell60 mL (¼ cup)0.12 – 0.26
Tahini/sesame seed butter15mL (1 Tbsp)0.19
Soy nuts60 mL (¼ cup)0.12
Yeast extract spread (marmite/vegemite)30 mL (2 Tbsp)3.56


High Doses of Thiamin

Thiamine is widely distributed into body tissues. Body stores of thiamine have been estimated to be limited to about 30 mg with about a 1 mg daily turnover. Decline in thiamine absorption occurs at intakes above 5 mg/day. Only a small percentage of a high dose of thiamin is absorbed, and elevated serum values result in active urinary excretion of the vitamin.

An experiment looking at three ranges of oral Thiamin doses (100mg, 500mg, 1500mg) found that these could elevate blood serum levels significantly [2].

It is interesting to note that tripling the dose from 500 mg to 1500 mg resulted in more than a tripling of peak serum levels. The authors concluded

our study demonstrates that high blood levels of thiamine can be achieved rapidly with oral thiamine hydrochloride. Thiamine is absorbed by both an active and unsaturable passive transport mechanism up to 1500 mg.

Peak Health Dose

If you are eating a healthy all year beach body diet that includes lots of veg, beans etc, then you shouldn’t need to take a supplementary Thiamin dose.

There is little research on the benefits of a higher dose of vitamin B1, although the Mayo Clinic offers doses of around 100mg per day for menstrual cramps and 50mg per day for epilepsy, so there may be some merit, and no risk, in taking these doses.

Vitamin B1 supplement buying guide

Unless you have a specific B1 deficiency, there’s no point in getting a separate Thiamine supplement. Instead, look at getting a full B vitamin complex supplement.


Meador K1, Loring D, Nichols M, Zamrini E, Rivner M, Posas H, Thompson E, Moore E. Preliminary findings of high-dose thiamine in dementia of Alzheimer’s type. J Geriatr Psychiatry Neurol. 1993 Oct-Dec;6(4):222-9.
Smithline HA1, Donnino M, Greenblatt DJ. Pharmacokinetics of high-dose oral thiamine hydrochloride in healthy subjects. BMC Clin Pharmacol. 2012 Feb 4;12:4.
Sauberlich HE, Herman YF, Stevens CO, Herman RH. Thiamin requirement of the adult human. Am J Clin Nutr. 1979 Nov;32(11):2237-48.

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