Background: Calcium is essential for skeletal mineralisation, neuromuscular function, coagulation and cellular signalling, and requirements are highest during periods of rapid childhood growth. Twenty-four-hour urinary calcium estimation remains the reference standard for assessing calcium excretion, but complete collection is difficult and often impractical in children. The spot urine calcium–creatinine ratio (UCCR) is a simple, non-invasive alternative that is widely used for paediatric screening.[5,6] Undernutrition may alter calcium handling through reduced intake, impaired absorption and compensatory hormonal adaptation, yet Indian data linking UCCR to nutritional status are limited.

Objectives: To assess nutritional status using anthropometry and to estimate the spot UCCR in children aged 1–15 years; and to determine the association of UCCR with age and nutritional status.

Methods: A hospital-based cross-sectional observational study was conducted in the Department of Paediatrics, Sree Mookambika Institute of Medical Sciences, over nine months (July 2025 to March 2026). Ninety children aged 1–15 years attending the paediatric outpatient and inpatient services were enrolled by non-probability consecutive sampling and stratified equally into three age groups (1–5, 6–10 and 11–15 years; n = 30 each). Weight, height, weight-for-age, height-for-age, weight-for-height, body mass index and mid-upper arm circumference (MUAC) were recorded. Calcium and creatinine were measured in early-morning spot urine samples and the UCCR was calculated as urinary calcium (mg/dL) divided by urinary creatinine (mg/dL).

Results: Mean UCCR declined progressively across age groups, from 0.15 ± 0.025 in children aged 1–5 years to 0.11 ± 0.032 at 6–10 years and 0.07 ± 0.046 at 11–15 years. Normal weight-for-age was present in 75/90 children (83.3%), normal height-for-age in 81/90 (90.0%) and normal weight-for-height in 78/90 (86.7%). By MUAC, 75/90 children (83.3%) were normal, 6/90 (6.7%) had moderate malnutrition and 9/90 (10.0%) had severe malnutrition. Children with normal anthropometric indices had higher UCCR values than underweight and malnourished children, and the association between nutritional status and UCCR was statistically significant.

Conclusion: The spot UCCR declines steadily with advancing age and is significantly influenced by nutritional status, with undernourished children excreting proportionally less calcium. UCCR is a practical, inexpensive and non-invasive index of calcium metabolism and nutritional adequacy in children.

KEYWORDS: Urine Calcium–creatinine Ratio, Children, Malnutrition, Nutritional Status, Calcium Metabolism, Anthropometry.