The document discusses several diseases and their associated nutrient deficiencies and treatments. Beriberi is caused by a thiamine deficiency and causes neurological issues, treated by thiamine supplements and intake of cereals, meats, and eggs. Pellagra results from niacin deficiency and causes memory loss and hallucinations, treated by niacin supplements and whole grains, legumes, and fish. Pernicious anemia occurs due to vitamin B12 deficiency and damages optic nerves and brain tissue, treated with B12 injections and organ meats, shellfish, and eggs.