Status of Common Water-Soluble Vitamins in Medical Students: A Cross-Sectional Analysis with Implications for Targeted Nutritional Screening Programs

Background/Objectives: Water-soluble vitamins are essential micronutrients requiring regular dietary replenishment due to minimal body storage capacity. Medical students.; despite their health knowledge, may be at risk for subclinical deficiencies due to academic stress and life-style factors. This study assessed water-soluble vitamin status to evaluate screening needs in this educated population. Methods: A cross-sectional study was conducted among 91 healthy medical students (age 18–23 years) at UAE University from September 2023 to January 2024. Serum levels of folate (B9), cobalamin (B12), and ascorbic acid (Vitamin C) were measured using validated high-performance chemiluminescent immunoassays. Demographic, anthropometric, dietary, and lifestyle data were collected via structured questionnaires. Statistical analyses included multivariate logistic regres-sion, correlation analyses, and receiver operating characteristic (ROC) curves. Results: Among the participants (70.3% female; mean age 19.8 ± 1.4 years; BMI 23.2 ± 2.9 kg/m2), vita-min C showed the highest prevalence of suboptimal levels at 7.7% (7/91 participants), comprising 2.2% with deficiency (<28 µmol/L, n = 2) and 5.5% with insufficiency (28–40 µmol/L, n = 5). Mean vitamin C was 56.7 ± 14.8 µmol/L. Vitamin B12 insufficiency (200–300 pg/mL) affected 9.0% (8/89) of students, with a mean of 485.3 ± 165.0 pg/mL. A non-significant trend toward higher insufficiency rates was observed among female students. No deficiencies were observed for folate (mean 14.1 ± 4.9 ng/mL). Multivariate analysis identified low fruit/vegetable intake (OR 4.8; 95% CI: 1.3–17.6; p = 0.018); high stress scores (OR 3.2; 95% CI: 1.1–9.4; p = 0.033); and female gender (OR 2.9; 95% CI: 0.9–9.1; p = 0.071) as predictors of suboptimal vitamin C. Vitamin C levels correlated positively with dietary quality (r = 0.412; p < 0.001) and negatively with stress scores (r = −0.241; p = 0.031). Despite being a health-educated population, nearly 10% of medical students demonstrated suboptimal water-soluble vitamin levels, particularly vitamins C and B12. Conclusions: These findings support implementing targeted screening programs focusing on high-risk groups, including students with poor dietary habits, high stress levels, or specific gender-based risks.