## 5 Effects of Micronutrient Supplementation on Weight Management and Metabolic Health in Obesity
### Effects of Micromutrient Supplementation on Glucose Homeostasis
The number of published studies on the effects of supplementation with vitamins A, B6, and B12 on glucose homeostasis is small, and no meta-analyses are available to date. Hence, for these micronutrients, the data in Table 5 were outsourced from RCTs. Vitamin A did not have a significant impact on the homeostasis of glucose in reproducteaged women (see Table 5). However, it was found to increase the phosphorylation of \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Micronutrient**} & \multirow{2}{*}{**Studied Group**} & \multirow{2}{*}{\begin{tabular}{c} **Number of** \\ **People** **Included** \\ \end{tabular} } & \multicolumn{4}{c}{**Measure (95\% Confidence Interval)**} & \multirow{2}{*}{**Reference**} \\ \cline{3-3} \cline{5-10}  & & & & **Effect** & & **FG (mg/dL)** & **FI (μIU/mL)** & **HOMA-IR** & **HbA1C (\%)** \\ \hline \multirow{2}{*}{Vit. E} & Patients with & & & & & & & \\  & diabetes & 2171 & MD & \(-3.4\) (\(-81.1\), \(4\)) & \(-1.1\) (\(-1.5\), \(-0.6\)) & \(-0.4\) (\(-0.8\), \(-0.1\)) & \(-0.2\) (\(-0.3\), \(-0.1\)) & [57] \\ \hline \multirow{2}{*}{Vit. C} & OW and OH adults & & & & & & & \\  & with T2D & 1447 & WMD & \(-10.7\) (\(-18.5\), \(-2.9\)) & \(-1.7\) (\(-3.2\), \(-0.3\)) & \(-0.9\) (\(-2.0\), \(0.3\)) & \(-0.5\) (\(-0.8\), \(-0.2\)) & [115] \\ \hline \multirow{2}{*}{Vit. B1} & Adults with T2D & 364 & MD & \(-3.6\) (\(-12.4\), \(5.2\)) & - & - & \(0.0\) (\(-0.4\), \(0.3\)) & [91] \\ \cline{2-10}  & \multirow{2}{*}{\
\begin{tabular}{c} Iranian /dieng \\ and OW women \\ \end{tabular} } & \multirow{2}{*}{4} & MD & \(-1.0\) (\(-5.0\), \(3.0\)) & \(-1.5\) (\(-2.2\), \(-0.8\)) & \(-0.5\) (\(-0.7\), \(-0.3\)) & - & [77] \\ \hline \multirow{2}{*}{Vit. B9} & Adults & 34,646 & WMD & \(-2.2\) (\(-3.7\), \(-0.7\)) & \(-0.2\) (\(-0.4\), \(-0.1\)) & \(-0.4\) (\(-0.7\), \(-0.1\)) & \(-0.3\) (\(-0.7\), \(0.2\)) & [116] \\ \hline \multirow{2}{*}{Vit. B12} & Iranian / adults with & & & & & & & \\  & NAFLD & 40 & DBM & \(-3.5\) (N/A) & \(-1.3\) (N/A) & \(-0.3\) (N/A) & - & [79] \\ \hline \multirow{2}{*}{Mg} & Adults & 1362 & WMD & \(-3.6\) (\(-81.0\), \(9\)) & \(-0.3\) (\(-14.0\)) & \(-0.7\) (\(-12.2\), \(-0.1\)) & \(0.0\) (\(-0.1\), \(0.1\)) & [117] \\ \hline \multirow{2}{*}{Se} & Adults & 1411 & WMD & \(-1.3\) (\(-4.0\), \(1.4\)) & \(-3.0\) (\(-5.1\), \(-0.9\)) & \(-0.8\) (\(-2.1\), \(0.5\)) & \(0.1\) (\(-0.2\), \(0.3\)) & [118] \\ \hline \multirow{2}{*}{Zn} & OW and OB adults & 651 & WMD & \(-86\) (\(-14.0\), \(-3.1\)) & \(-0.8\) (\(-2.5\), \(-0.9\)) & \(-0.5\) (\(-0.8\), \(-0.3\)) & \(-0.3\) (\(-0.4\), \(-0.1\)) & [119] \\ \hline \multirow{2}{*}{Cr} & Patients with T2D & 1350 & WMD & \(-91.0\) (\(-36.2\), \(-1.9\)) & \(-1.8\) (\(-2.6\), \(1.0\)) & \(-1.5\)(\(-2.4\), \(-0.7\)) & \(-0.7\) (\(-1.2\), \(-0.2\)) & [60] \\ \cline{2-10}  & \multirow{2}{*}{
\begin{tabular}{c} FG—Fasting glucose, FI—Fasting insulin, HOMA-IR—Homestestatic model assessment for insulin resistance, HbA1C—Glycated hemoglobin, OB—obesity, OW— overweight, T2D—type 2 diabetes mellitus, NAFLD—non-alcoholic fatty liver disease, MD—mean difference, WMD—weighted mean difference; ‘denotes patients eligible to participate in the study carried out in this country. In light grey, statistically significant findings (\(p<0.05\)) were highlighted. \\ \hline \hline \end{tabular}
\end{table} 
Table 5: _Cont._insulin receptors in WNIN/Ob rats [128]; therefore, it could possess insulin resistance modulatory properties, and further research should be carried out to optimize effects achieved in humans. The recent findings of clinical trials demonstrated the positive effects of vitamin B6 on glucose homeostasis. For example, RCT with the participation of women with excess weight undergoing an 8-week weight reduction program (see Table 5) showed that such supplementation had a significant, positive effect on FI and HOMA-IR compared to the control group receiving a placebo [77].