Endemic Chronic Fluoride To ity and Dietary Calcium Deficiencv Interaction Syndromes of Metabolic Bone Disease and Deformities In India By M. Teotia, S.P.S. Teotia and K.P. Singh

Epidemiological studies during Year 1963-1997 were conducted in 45,725 children exposed to high intake of endemic fluoride in the drinking water since their birth. Children with adequate (dietary calcium > 800 mg/d) and inadequate (dietary calcium < 300 mg/d) calcium nutrition and with comparable intakes of fluoride (mean 9.5 _ 1.9 mg/d) were compared. The toxic effects of fluoride were severe and more complex and the incidence of metabolic bone disease (rickets, osteoporosis. PTH bone disease) and bony leg deformities (genu valgum, genu varum, bowing, rotational and wind-swept) was greater (> 90%) in children with calcium deficiency as compared to < 25% in chil- dren with adequate calcium who largely had osteosclerotic form of skeletal fluorosis with minimal secondary hyperparathyroidism.