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 D deficiency with primary hyperparathyroidism) or with hypoparathyroidism. Patients with chronic liver disease or intestinal malabsorption disorders may also require larger doses of vitamin D (up to 40,000 IU or 1 mg (1000 micrograms) daily). The estimated percentage of the population with a vitamin D deficiency varies based on the threshold used to define a deficiency. Recommendations for 25(OH)D serum levels vary across authorities, and probably vary based on factors like age; calculations for the epidemiology of vitamin D deficiency depend on the recommended level used. A 2011 Institute of Medicine (IOM) report set the sufficiency level at 20 ng/ml (50 nmol/l),