***TASK***
the task is to simplify the input abstract of a biomedical literature

***INPUT***
the input is the abstract of a biomedical literature

***OUTPUT***
the output is the simplified abstract for the input abstract of a biomedical literature

***DOCUMENTATION***

***EXAMPLES***

Input: Four studies enrolled approximately 1700 participants. Trials lasted between nine months to two years. Three studies were randomised controlled trials, two of which showed a cluster randomised design; one trial probably was a controlled trial with researcher controlled group assignment. In children up to three years of age in Turkey, Vitamin D compared to no intervention showed a relative risk of 0.04 (95% confidence interval (CI) 0 to 0.71). Despite a marked non-compliance, a Chinese trial in children up to three years of age comparing a combined intervention of supplementation of vitamin D, calcium and nutritional counselling showed a relative risk of 0.76 (95% CI 0.61 to 0.95) compared to no intervention. In two studies conducted in older children in China and in France no rickets occurred in both the intervention and control group. There a only few studies on the prevention of nutritional rickets in term born children. Until new data become available, it appears sound to offer preventive measures (vitamin D or calcium) to groups of high risk, like infants and toddlers; children living in Africa, Asia or the Middle East or migrated children from these regions into areas where rickets is not frequent. Due to a marked clinical heterogeneity and the scarcity of data, the main and adverse effects of preventive measures against nutritional rickets should be investigated in different countries, different age groups and in children of different ethnic origin.
Output:

Four trials enrolled approximately 1700 participants and lasted between nine months and two years. Study participants were aged from one month to 15 years. There were different results on the occurrence of nutritional rickets in different settings. Adverse effects were investigated in one study only.  Considering the partial high frequency of nutritional rickets, the obvious way of action of supplementation of vitamin D or calcium and the favourable risk-benefit ratio, preventive measures are reasonable in high risk groups like infants and toddlers. New studies investigating main and side effects of preventive measures against nutritional rickets in different age groups and in different countries are indicated.