Some observations on the effects of vitamin C deficiency on bone.

Young guinea-pigs were given a scorbutic diet, and some subsequently allowed to recover. When killed, vessels were perfused with a mixture of Micropaque and Berlin blue. Walls of vessels formed during the period of ascorbic acid deficiency were weak. Sometimes bursts were surrounded by granulation tissue. Other weak patches burst as the perfusion medium was injected. All the sinusoid vessels were dilated, and blood flow in the bones was sluggish. Bone turnover was affected. The impaired blood flow caused resorption, in a manner analogous to bone removal in disuse osteoporosis. Impaired matrix production caused a cessation of osteoblastic activity. The resultant osteoporosis is particularly severe during growth. In the growth cartilage the calciflable matrix was defective, with its nucleation centres immediately available, so that some calcification was observed from the level of the base of the proliferative zone. Nucleoli in the osteogenic and connective tissue cells of scorbutic animals were abnormally large and dense. It is possible that they contained the RNA granules which would normally have been spread over endoplasmic reticulum membranes.