The supplementary effects of omega-3 fatty acid alone and in a combination with vitamin D3 on serum leptin levels: A randomized clinical trial on men and women with vitamin D deficiency

Abstract

Purpose: This randomized clinical trial (RCT) was designed to assess the effect of VD3, n-3FA, and their combination on serum leptin levels in people with vitamin D deficiency (VDD). Subjects and methods: One hundred and forty six participants, were randomly assigned into four groups supplemented with the dose of 50,000 IU VD3 taken weekly (D), 300 mg n-3FA taken daily (Om), and their combination (D+Om) or control (C) for eight weeks. Fasting baseline and follow-up (10 weeks; 8 weeks supplementation plus washout period of 2 weeks) of serum 25 hydroxyvitamin D (25OHD), leptin, glucose, triglycerides (TG), parathyroid hormone (PTH), calcium, and phosphorus were assayed. A paired T-test was used to assess the changes in serum leptin levels over of the follow-up period. Results: Significant increase in follow-up serum leptin (10.62 ± 7.18 to 14.42 ± 8.29 ng/mL, P = 0.002) and TG (154 ± 84.4 to 200.1 ± 79, P = 0.015) levels were observed in n-3-FA supplemented group. Combination therapy (VD3 plus n-3 FA) significantly increased serum 25OHD (13.49 ± 4.64 to 37.09 ± 11.13 ng/mL, P < 0.001), TG levels (114.3 ± 57.3 to 139.1 ± 60.7 mg/mL, P = 0.007) and insignificantly serum leptin (6.74 ± 4.87 to 8.01 ± 6.77 ng/mL, P = 0.269). Conclusion: Our study referred that notable elevation in leptin and TG levels might be linked to leptin resistance. However, further RCTs are required to clarify possible consequences resulted from the extensive administration of n-3FA supplements and their combinations with high doses of VD3 supplements on humans’ health.

The effects of vitamin D and omega-3 co-supplementation on lipid profile in adults: a systematic review and meta-analysis

“…, 2017; Rajabi-Naeeni et al ., 2020) included only women, and the remaining four studies (Lee et al. , 2015; Abu-Samak et al. , 2021; Kouchaki et al.…”

“…The full texts of the remaining 14 articles were then examined, and 8 of them were excluded for not reporting the desired data or not being randomized. Eventually, this systematic review and meta-analysis comprised six RCTs (Jamilian et al, 2017;Lee et al, 2015;Abu-Samak et al, 2021;Kouchaki et al, 2018;Rajabi-Naeeni et al, 2020;Talari et al, 2019). A flow diagram of the study selection is shown in Figure 1.…”

“…We pooled data from 6 eligible studies with 355 participants, 187 participants in the intervention group and 168 participants in the placebo group. All of the trials were published between 2015 and 2021, and study locations included Iran (Jamilian et al, 2017;Kouchaki et al, 2018;Rajabi-Naeeni et al, 2020;Talari et al, 2019), Korea (Lee et al, 2015) and Jordan (Abu-Samak et al, 2021). Treatment duration ranged from 6 to 24 weeks, while the number of subjects per study ranged from 15 to 84.…”

“…These studies prescribed different doses of omega-3 that ranged from 300 to 2,000 mg/day. Finally, two studies (Jamilian et al, 2017;Rajabi-Naeeni et al, 2020) included only women, and the remaining four studies (Lee et al, 2015;Abu-Samak et al, 2021;Kouchaki et al, 2018;Talari et al, 2019) included both women and men. The summary of the characteristics of the included studies is shown in Table 1.…”