Ultra Fast Keto Boost and beef liver, mackerel , salmon , white beans , buckwheat, soyAbove 1 mg wheat bran, wheat germDepartment of Hygiene of Human Nutrition, PoznaĆ 2000Bibliography: Nutrition standards for the Polish population - amendment , Institute of Food and Nutrition, Warsaw 2012Vitamin B1 (thiamine) is involved in the proper functioning of the nervous system, muscles and heart. Vitamin B1 is therefore necessary in the daily diet, and its deficiency can have serious effects. In extreme cases, beriberi disease may develop, i.e. muscle disorders, cardiovascular failure, which can even lead to death.