Vitamin K deficiency thus activate) certain enzymes involved in coagulation: Factors II, VII, IX, X, and protein C and protein S. Inability to activate the clotting cascade via these factors leads to the bleeding symptoms mentioned above. Notably, when one examines the lab values in Vitamin K deficiency [see below] the prothrombin time is elevated, but the partial thromboplastin time is normal or only mildly prolonged. This may seem counterintuitive given that the deficiency leads to decreased activity in factors of both the intrinsic pathway (F-IX) which is monitored by PTT, as well as the extrinsic pathway (F-VII) which is monitored by PT.
Vitamin D deficiency in the diet, and decreased skin thickness which leads to further decreased absorption of vitamin D from sunlight. Although rickets and osteomalacia are now rare in Britain, osteomalacia outbreaks in some immigrant communities included women with seemingly adequate daylight outdoor exposure wearing typical Western clothing. Having darker skin and reduced exposure to sunshine did not produce rickets unless the diet deviated from a Western omnivore pattern characterized by high intakes of meat, fish, and eggs, and low intakes of high-extraction cereals. In sunny countries where rickets occurs among older toddlers and children, vitamin D deficiency has been attributed to low