The present randomized clinical trial (RCT) was conducted on Jordanian participants with vitamin D deficiency (VDD) with no other medical conditions, to evaluate the combined effect of 1, 25-dihydroxy vitamin D 3 (Vit. D 3) and omega-3 fatty acid (n-3FA) supplements (D+) on oxidized low-density lipoprotein (Ox-LDL) and non–high-density lipoprotein cholesterol (non–HDL-C) levels as common predictors of cardiovascular diseases (CVDs). Participants were randomized into 4 groups as follows: a control group (C) that received no supplementations, a Vit. D 3 group that received 50,000 IU of Vit. D 3 every week, an n-3FA group that received 300 mg of omega-3 fatty acid every day, and a D+ group that received a combination of both supplements, with the same dosage administered by the previous groups but with a 4–6-hour time interval between Vit. D 3 and n-3FA administration to avoid any possible interaction. All supplementations were administered orally for 8 weeks. Forty-seven participants were allocated to each group. Twenty-six in the control group, 37 participants in the Vit. D 3 group, 37 participants in the n-3FA group, and 46 participants in the D+ group completed the study to the end. The D+ supplementations significantly increased non–HDL-C (118.99±60.98 to 155.26±43.36 mg/dL, P<< 0.05) but decreased Ox–LDL-C levels (69.29±37.69 to 52.81±17.30 pg/mL, P= 0.03). The stepwise regression showed that the serum LDL-C level was the main independent variable involved in the elevation of non-HDL levels (R 2= 0.837) observed at the end of the trial in the D+ group. The groups that were supplemented with either Vit. D 3 alone or n-3FA alone had an insignificant decrease in the level of Ox–LDL-C. In conclusion, despite the observed hyperlipidemic effect, the combination treatment is recommended by the research team because the decrease in Ox-LDL may offset the hyperlipidemic effect.