The aim of our study focused on prevention of osteoporosis was to assess the prevalence of selected risk factors in two samples of Czech children, calcium intake, smoking and alcohol consumption. In a sample of 980 children of two age groups, junior and senior school age, we found an inadequate intake of calcium, 723 mg and 646 mg in junior and senior aged children, resp. This intake seems is only 66 and 54 % of RDA in juniors and seniors, resp., that means an absolutely insufficient daily amount. In a group of 6050 children a significant increase of regular smokers was been observed: 3.0 % children smoked regularly when they were 11 years old and 16.6 % children at their age 14 years. During the same period also the prevalence of those who reported drinking of alcoholic beverages almost doubled: from 38.7 % to 61.0 %. It may be expected, that osteoporosis will be an important and public health problem in the middle of the next century.

        Key words: prevention of osteoporosis, calcium intake, smoking in children, alcohol consumption in children