Effect of calcium and vitamin D on growth, rickets and Kashin-Beck disease in 0- to 5-year-old children in a rural area of central Tibet.

OBJECTIVE: To evaluate the effect of calcium (15 mmol/day) and vitamin D (625 µg/month), as single supplement or in combination, vs. no supplement on growth, clinical signs of rickets and Kashin-Beck disease (KBD) and dental health. METHODS: Prospective controlled trial involving children aged 0-5 years living in four groups of villages in a KBD-endemic rural area of central Tibet who received either calcium and/or vitamin D or no supplement. The cohort was followed over 3 years. Primary outcome was the impact of the different supplementation regimes on KBD, rickets and growth; secondary outcomes were impact on urinary levels of calcium and phosphorus, biomarkers of bone and cartilage turnover, and dental health. RESULTS: No difference was observed between the four groups with regard to anthropometric data, rickets, KBD, urinary levels of CrossLaps(®) and CartiLaps(®) . Weight for height or age, mid-upper arm circumference and skinfold thickness decreased in the four groups. Height for age increased and the prevalence of KBD fell in the four groups. Dental health was better in the group receiving calcium and vitamin D. Urinary calcium levels increased after 3 years of follow-up in all groups; the group receiving vitamin D had a higher increase (P-value: 0.044). The same global increase was observed for urinary phosphorus levels; the group receiving calcium had a higher increase (P-value: 0.01). CONCLUSIONS: Calcium and vitamin D failed to improve growth and bone metabolism of children living in a KBD-endemic rural area. Calcium and vitamin D supplementation improved dental health.

Growth, nutritional status, and signs of rickets in 0-5-year-old children in a Kashin-Beck disease endemic area of Central Tibet.

UNLABELLED: In order to describe the growth of 0-5-year-old Tibetan children living in a Kashin-Beck disease (KBD) endemic rural area and to examine the relationship between anthropometric indicators and clinical signs of rickets, we analyzed the baseline data of a cohort of 668 children enrolled in a prospective program of calcium and vitamin D supplementation. Tibetan children suffer from growth retardation. Z score of weight-for-age, height-for-age, weight-for-height was below -2 in 32.5%, 27.7%, and 12.1% of the children, respectively. Clinical signs of severe rickets are highly prevalent. Underweight, stunting, and clinical rickets increases with age. Prevalence of malnutrition was higher in the presence of signs of rickets. The proportion of children with a head circumference Z score < -2 was lowest when signs of rickets were observed. CONCLUSION: Stunting and underweight are frequent and probably associated with rickets.