Toxicological study of calcium from Jeju Lava Seawater: acute and 90-day repeated-dose oral administration in rats

A series of toxicity trials was conducted to analyze the acute and subchronic oral toxicity of calcium from Jeju Lava Seawater (CJLS) in Sprague-Dawley rats. In the acute toxicity trial, rats were administered 0 or a daily dose of 2,000 mg/kg body weight (BW) of CJLS. General behavior, side effects, and mortality were monitored over 14 days. In the subacute and subchronic trials, daily doses of 0, 250, 500, or 1,000 mg/kg BW were administered to the rats over 28 and 90 days, respectively. Clinical signs were examined daily, and changes in body weight, relative organ weight (ROW), and hematological, biochemical, and pathological parameters were recorded. The acute toxicity trial showed that the maximum tolerated dose of CJLS was >2,000 mg/kg BW, with no adverse effects or mortality observed during the 14-day period. In subacute and subchronic trials, oral administration of CJLS at a dosage of 1,000 mg/kg BW/day did not result in significant changes in BW, ROW, or hematological and biochemical biomarkers. These results indicate that the oral administration of CJLS at doses lower than 1,000 mg/kg BW/day is safe for rats, providing a basis for the clinical use of CJLS.