Scurvy cases (notably French soldiers eating fresh horse meat), it was discovered that meat alone, even partly cooked meat, could alleviate scurvy. Conversely, in other cases, a meat-only diet could cause scurvy. Scott's 1902 Antarctic expedition used lightly fried seal meat and liver, whereby complete recovery from incipient scurvy was reported to have taken less than two weeks. Hippocrates documented scurvy as a disease, and Egyptians have recorded its symptoms as early as 1550 BCE. The knowledge that consuming foods containing vitamin C is a cure for scurvy has been repeatedly rediscovered and forgotten into the early 20th century. In the
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