Investigating Nutritional Deficiencies and Lifestyle Factors Contributing to Rising Incidence of Rickets among Children in Developing Regions

Background: Nutritional rickets persists in many low- and middle-income countries despite abundant sunlight, driven by a complex interplay of inadequate dietary intake, limited effective sunlight exposure, and evolving lifestyle patterns among children. Objective: To examine the association between dietary calcium and vitamin D intake, sunlight exposure, lifestyle behaviours, and rickets-related outcomes among children in urban and semi-urban settings in Pakistan. Methods: A cross-sectional study was conducted over four months among 410 children aged 1–12 years selected through multistage sampling from healthcare facilities and schools. Data were collected using an interviewer-administered questionnaire, semi-quantitative food frequency questionnaire, 24-hour dietary recall, and a Sunlight Exposure Index. Anthropometry and standardised clinical assessment for rickets were performed, and available biochemical data were extracted from records. Descriptive statistics, t-tests, ANOVA, Pearson’s correlation, and multiple linear regression were applied using SPSS version 26. Results: Mean daily calcium and vitamin D intakes were 528 ± 211 mg and 3.8 ± 1.9 µg, respectively, with fewer than 21% of children meeting age-specific recommendations. Overall, 16.8% had clinical or radiographic features consistent with rickets. Lower calcium intake, reduced daily sunlight exposure, lower Sunlight Exposure Index scores, and shorter outdoor play time were significantly associated with rickets indicators. In multivariable models, inadequate calcium intake and limited sunlight exposure remained the strongest independent predictors. Conclusion: Inadequate intakes of calcium and vitamin D, combined with limited effective sunlight exposure and sedentary lifestyles, are major determinants of rickets-related outcomes among children in this setting, highlighting the need for integrated nutritional and behavioural interventions.