Thiamine :- Thiamine is also known as Anti-beriberi vitamin. Deficiency of thiamine leads to a condition called as Beriberi. Beriberi is of 2 types:

 » Dry Beriberi which predominantly affects the nervous system and leads to irritability, fatigue, headache, calf muscle pain, difficulty in standing from sitting position, constipation, slow growth and gradual wasting. Patient on examination is found to have neuritis. In infants, it may lead to tremors, convulsions and squint.
 » Wet Beriberi affects the heart, predominantly and leads to palpitations, a fast pulse, breathlessness and swelling over the feet. In infants (children less than 1 year of age) in addition leads to shrill cry, vomiting and bluish hue to the skin.

In addition, in infants a third-type of Beriberi may occur which is known as Aphonic Beri Beri in which the infant presents with hoarse cry which then leads to absent voice and finally may lead to breathlessness and swelling over the body.

Deficiency of Thiamine is quite rare as thiamine is present in cereals pulses, groundnuts and vegetables. Diagnosis of thiamine deficiency is made clinically. Dramatic improvement is seen in symptoms on supplementation with thiamine.

Rare genetic disorders can occur due to deficiency of enzymes in the body that process thiamine leading to anemia (low hemoglobin) and mental retardation. In these conditions, thiamine supplementation in high doses in required for a prolonged period of time.