This cross-sectional study (May–August 2024) assessed vitamin D and calcium deficiency in 50 preschool-aged children in Bin Jawad, Libya. Blood tests and maternal questionnaires revealed that 60% of children had vitamin D deficiency: 12% very severe (<10 ng/mL), 32% severe (10–20 ng/mL), and 16% moderate (21–29 ng/mL). Deficiency was slightly more common in girls (68%) than boys (52%), but the difference was **not statistically significant (p = 0.746). Deficiency rates across age groups (7–24, 25–36, and 37–60 months) were 60%, 63%, and 56%, respectively, with the oldest group showing the highest proportion of normal vitamin D levels (≥30 ng/mL).Calcium deficiency was found in 18% of boys and 8% of girls, with no significant association between vitamin D and calcium deficiency (p = 0.232). Key risk factors included inadequate sun exposure (68% had irregular exposure; 20% had none) and low breastfeeding rates (80% were not breastfed). The study recommends increased sunlight exposure, nutritional education, and supplementation programs to combat these deficiencies.