ABSTRACT Aim This study aimed to determine age‐related reference values, focusing on infant urinary solute‐to‐urinary creatinine concentration ratios (urinary calcium, urinary phosphate, urinary sodium, urinary magnesium, urinary potassium) in healthy Saudi infants aged 0–2 years. Additionally, we calculated the calcium‐to‐sodium ratio (UCa/UNa) to assess the relationship between urinary sodium and calcium excretion. Methods This longitudinal study recruited healthy infants and toddlers from King Khalid University Hospital's Well Baby clinic, Riyadh, Saudi Arabia. Urine solute and creatinine concentrations were measured using standardised laboratory methods. Ratios of urinary calcium/creatinine (UCa/Cr), sodium/creatinine (UNa/Cr), potassium/creatinine (UK/Cr), magnesium/creatinine (UMg/Cr), phosphate/creatinine (UP/Cr) and calcium/sodium (UCa/UNa) were calculated. Subjects were categorised into Group A (0–2 months) and Group B (2 months–2 years). Data were analysed using median, interquartile range (IQR), Shapiro–Wilk and Mann–Whitney U tests. Results A total of 189 healthy children (116 males) were enrolled (Group A: 61.3%; Group B: 38.6%). Significant differences were observed between Group A and Group B for UCa/Cr, UMg/Cr, UNa/Cr, UK/Cr ( p 0.05). Conclusion This study established age‐related reference values for urinary solute‐to‐creatinine ratios in Saudi infants, revealing significant differences between age groups. Elevated UCa/Cr in younger infants aligns with physiological patterns. These findings underscore the importance of establishing population‐specific reference values to provide a suitable context for evaluating urinary calcium excretion in Saudi children, which may help prevent both overdiagnosis and underdiagnosis of hypercalciuria in this population.
Alhasan et al. (Mon,) studied this question.