Adrenal and hepatic calcium stearate crystal deposits in dogs fed a thiamine-deficient diet.

The nature and histologic environment of birefringent crystals found incidentally at necropsy in the liver and adrenal glands of dogs fed a thiamine-deficient diet were studied. The crystals were identified as calcium stearate by ultrastructural and x-ray microdiffraction techniques. Crystals were observed intracellularly within cytoplasmic vacuoles and extracellularly within sinusoids. Generally, crystals were also observed in pair-fed controls that were given a purified diet (equal in weight to that consumed by the thiamine-deficient animals) plus supplemental thiamine. Crystal deposits were found in trace amounts in a few of the ad libitum-fed controls. Although thiamine deficiency may be involved in promoting crystal deposition in the adrenal cortex, calcium stearate crystal formation within the adrenal glands and the liver appears unrelated to dietary thiamine deficiency per se, but is probably related to deficiency of an unidentified nutrient in the purified thiamine-deficient diet.