Table 3 Factors associated with 25(OH)D by multiple linear regression for the period between December–March (n = 802)

mUVI

−0.149 (−0.211; −0.087)

< 0.001

Age (years)

−0.210 (−0.276; −0.146)

< 0.001

Residence

−0.104 (−0.169; −0.041)

0.001

Household income (€/month) - ≥1000

0.147 (0.082; 0.211)

< 0.001

Household income (€/month) - 500-999

0.069 (0.006; 0.132)

0.032

Alcoholic beverages consumption - Moderate

0.070 (0.009; 0.132)

0.025

Self-perceived health - Bad

−0.082 (−0.144; −0.020)

0.010

Supplement intake

0.196 (0.133; 0.256)

< 0.001

Undernutrition status (MNA-SF score)

0.097 (0.034; 0.159)

0.003

BMI (kg/m²)

−0.164 (−0.226; −0.102)

<0.001