Scurvy Campaign had a lack of vitamin C in their diet which caused many of the soldiers to contract scurvy. It is thought that scurvy is one of many reasons that the Allied attack on Gallipoli failed. Vilhjalmur Stefansson, an arctic explorer who had lived among the Inuit, proved that the all-meat diet they consumed did not lead to vitamin deficiencies. He participated in a study in New York's Bellevue Hospital in February 1928, where he and a companion ate only meat for a year while under close medical observation, yet remained in good health. In 1927, Hungarian biochemist Szent-Györgyi isolated
Vitamin B12 deficiency years worth of vitamin B under normal conditions and functioning. However, the rate at which B levels may change when dietary intake is low depends on the balance between several variables. Vitamin B deficiency causes particular changes to the metabolism of two clinically relevant substances in humans: Methionine is activated to "S"-adenosyl methionine, which aids in purine and thymidine synthesis, myelin production, protein/neurotransmitters/fatty acid/phospholipid production and DNA methylation. 5-Methyl tetrahydrofolate provides a methyl group, which is released to the reaction with homocysteine, resulting in methionine. This reaction requires cobalamin as a cofactor. The creation of 5-methyl tetrahydrofolate is an irreversible