The combination of omega-3 fatty acids with high doses of vitamin D3 elevate A1c levels: A randomized Clinical Trial in people with vitamin D deficiency

Purpose: This randomised clinical trial (RCT) was created to assess the influence of 1,25-dihydroxyvitamin D (VD3), omega-3 fatty acids (n-3FA) and their combination (D+) on glycated haemoglobin (A1c) levels in Jordanian peoples with vitamin D deficiency (VDD). Participants and Methods: This RCT was designed to examine the follow-up (2 months) effect of either 50 000 IU VD3, 300 mg n-3FA, or the combination of the two supplements on glycated Haemoglobin (A1c) levels in 146 Jordanian women and men with VDD, aged from 25 to 55 years. The eligible participants were randomised into four groups: Control (C); VD3 supplementation (50 000 IU of VD3 was taken weekly) (D-3); n-3FA supplementation (300 mg of omega-3FA was taken daily) (n-3FA); VD3 and omega-3 supplementation group (D+) with the same protocol as the previous two groups. Results: The combination therapy (n-3FA plus VD3) for 8 weeks significantly increased A1c levels (5.79 +/- 0.34 vs 5.41 +/- 0.33, P < .001). Tukey test for post hoc comparisons of A1c at follow-up showed that the A1c mean levels were remarkably higher in the D+ study group comparing to the control group (5.78 vs 5.38). Conclusion: The intervention of n-3FA alone or in combination with high doses of VD3 may lead to negative effects on glycaemic control or accelerate the insulin resistance's development in susceptible people for diabetes mellitus (type 2).