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Comparative effects of vitamin and mineral supplements in the management of type 2 diabetes in primary care: A systematic review and network meta-analysis of randomized controlled trials.
Xia, J, Yu, J, Xu, H, Zhou, Y, Li, H, Yin, S, Xu, D, Wang, Y, Xia, H, Liao, W, et al
Pharmacological research. 2023;188:106647
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Plain language summary
Type 2 diabetes mellitus (T2DM), characterised by sustained hyperglycaemia and insulin resistance, remains a severe driver of chronic metabolic diseases such as cardiovascular diseases. The aim of this study was to investigate and compare the efficacy of vitamin and mineral supplements in the management of glycaemic control and lipid metabolism for type 2 diabetic patients to inform clinical practice. This study is a systematic review and meta-analysis of one hundred and seventy articles with a total of 4223 adults with T2DM. Participants were randomised to either the placebo/no treatment group (n= 6345) or to the treatment group (n= 7878). Results show that: - chromium was the most effective micronutrient for decreasing fasting blood glucose and insulin resistance. - vitamin K was the top-ranked micronutrient in reducing haemoglobin A1C and fasting insulin levels. - vanadium was the top-ranked micronutrient in total cholesterol reductions. - niacin was ranked as the most effective in triglycerides reductions and increasing high-density lipoprotein cholesterol levels. - vitamin E was the top-ranked micronutrient in low-density lipoprotein cholesterol reductions. Authors conclude that micronutrient supplements especially chromium, vitamin E, vitamin K, vanadium, and niacin supplements, may be more effective in the management of T2DM compared with other micronutrients.
Expert Review
Conflicts of interest:
None
Take Home Message:
- Clinicians could consider the adjunctive effect of micronutrients supplements, such as chromium, vitamin E, vitamin K, vanadium, and niacin supplements in a nutrition protocol to manage T2DM and slow or prevent its complications.
- The study authors state that the vitamin and mineral supplements under review had a statistically significant improvement, however they did not reach the study threshold for clinical significance. Therefore they advise caution in utilising micronutrient supplements in the management of glucose and lipid metabolism for T2DM.
Evidence Category:
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X
A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Objectives
The aim of this systematic review was to evaluate the comparative effects of vitamin and mineral supplements on managing glycemic control and lipid metabolism for type 2 diabetes mellitus (T2DM).
Methodology
This systematic review is registered with PROSPERO and adhered to PRISMA-2020 guidelines for network meta-analysis
The Cochrane Collaboration’s risk-of-bias tool was used to assess eligible randomised trials
8 prespecified markers identified and assessed in this study : 1) HbA1c (%), 2) fasting blood glucose (mmol/L), 3) total cholesterol (mmol/L), 4) triglycerides (mmol/L), 5) fasting insulin (μIU/mL), 6) HOMA-IR, 7) LDL-c (mmol/L), and 8) HDL-c (mmol/L).
Results
- 170 RCT trials of 14223 participants with T2DM treated with vitamin supplements, mineral supplements, or placebo/no treatment were included
- Low to very low certainty evidence established chromium supplements as the most effective in reducing fasting blood glucose levels and homeostasis model assessment of insulin resistance (SUCRAs: 90.4% and 78.3%, respectively)
- Vitamin K supplements ranked best in reducing glycated haemoglobin A1c and fasting insulin levels (SUCRAs: 97.0% and 82.3%, respectively), with moderate to very low certainty evidence
- Vanadium supplements ranked best in lowering total cholesterol levels with very low evidence certainty (SUCRAs:100%)
- Niacin supplements ranked best in triglyceride reductions and increasing high-density lipo-protein cholesterol levels with low to very low evidence certainty (SUCRAs:93.7% and 94.6%, respectively)
- Vitamin E supplements ranked best in reducing low-density lipoprotein cholesterol levels with very low evidence certainty (SUCRAs:80.0%).
Conclusion
- Micronutrient supplements, such as chromium, vitamin E, vitamin K, vanadium, and niacin supplements, may be efficacious in managing T2DM
- It should be noted that the evidence certainty for all was low.
Clinical practice applications:
- Chromium plays an important role in carbohydrate and lipid metabolism and was the most effective micronutrient for decreasing fasting blood glucose, HbA1c, fasting insulin, and HOMA-IR reductions. More pronounced effects were seen for chromium than vitamin E, vitamin C, niacin, selenium, and magnesium supplements
- Vitamin K was the top-ranked micronutrient in reducing HbA1c and fasting insulin levels. The mechanism through which Vitamin K affects glucose metabolism is proposed as activation of the AMP-activated protein kinase/sirtuin 1, that in turn increases phosphocreatine 3-kinase and glucose transporter 2 to decrease insulin resistance and fasting glucose.
- Vanadium was the top-ranked micronutrient in total cholesterol (TC) reductions, where supplementation dosage should be carefully considered, as vanadium compounds can be moderately or highly toxic. Vanadium supplementation is only recommended in cases of vanadium deficiency or diabetes, hyperlipidemia, and hypertension, where the intake of vanadium from food should be enhanced in preference to supplementation
- Niacin was ranked as the most effective in triglyceride (TG) reductions and increasing HDL cholesterol levels. The dose of niacin could not be determined
- Vitamin E was the top-ranked micronutrient in low-density lipo- protein (LDL) cholesterol reductions.
Considerations for future research:
- Considering the clinical importance of these findings, new research is needed to get better insight into the efficacy of micronutrient supplements in managing T2DM
- Selenium homeostasis, selenoprotein, insulin signaling/secretion, and carbohydrate/lipid metabolism are linked in multiple and complex ways but the authors could not explain why chromium supplementation would lower blood glucose more effectively than selenium supplementation, and suggest more research is needed to clarify this
- While vitamin K status could be an emerging treatment target in T2DM prevention and management, it remains to be determined whether vitamin K supplementation has an advantage over other nutrients in terms of hypoglycemic effect, and further research is necessary
- The beneficial effect of vitamin E and niacin supplements regarding lipid metabolism warrant investigation through more rigorous comparative studies.
Abstract
Medical nutrition treatment can manage diabetes and slow or prevent its complications. The comparative effects of micronutrient supplements, however, have not yet been well established. We aimed at evaluating the comparative effects of vitamin and mineral supplements on managing glycemic control and lipid metabolism for type 2 diabetes mellitus (T2DM) to inform clinical practice. Electronic and hand searches for randomized controlled trials (RCTs) were performed until June 1, 2022. We selected RCTs enrolling patients with T2DM who were treated with vitamin supplements, mineral supplements, or placebo/no treatment. Data were pooled via frequentist random-effects network meta-analyses. A total of 170 eligible trials and 14223 participants were included. Low to very low certainty evidence established chromium supplements as the most effective in reducing fasting blood glucose levels and homeostasis model assessment of insulin resistance (SUCRAs: 90.4% and 78.3%, respectively). Vitamin K supplements ranked best in reducing glycated hemoglobin A1c and fasting insulin levels (SUCRAs: 97.0% and 82.3%, respectively), with moderate to very low certainty evidence. Vanadium supplements ranked best in lowering total cholesterol levels with very low evidence certainty (SUCRAs:100%). Niacin supplements ranked best in triglyceride reductions and increasing high-density lipoprotein cholesterol levels with low to very low evidence certainty (SUCRAs:93.7% and 94.6%, respectively). Vitamin E supplements ranked best in reducing low-density lipoprotein cholesterol levels with very low evidence certainty (SUCRAs:80.0%). Our analyses indicated that micronutrient supplements, especially chromium, vitamin E, vitamin K, vanadium, and niacin supplements, may be more efficacious in managing T2DM than other micronutrients. Considering the clinical importance of these findings, new research is needed to get better insight into this issue.
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Zinc supplementation affects favorably the frequency of migraine attacks: a double-blind randomized placebo-controlled clinical trial.
Ahmadi, H, Mazloumi-Kiapey, SS, Sadeghi, O, Nasiri, M, Khorvash, F, Mottaghi, T, Askari, G
Nutrition journal. 2020;19(1):101
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Plain language summary
Migraine is a chronic neurovascular disorder. Patients with this disorder suffer from severe headaches and also nausea, vomiting, photophobia, and phonophobia during a migraine attack. Several supplementary treatments have been suggested for the management of migraine symptoms. Among these methods, there is the supplementation with micronutrients. The aim of this study was to examine the effect of zinc supplementation on characteristics of migraine attacks in migraine patients. This study is a double-blind randomized clinical trial which included migraine patients, with an age range between 20 and 60 years. Patients were stratified based on age (20–40 and 40–60 years), gender (male and female), and body mass index (18.5–24.9 and 25–30) into different blocks. Then, they were randomly allocated to the intervention or control groups. Results show that when compared to the placebo group, zinc supplementation resulted in a significant reduction in headache severity and migraine attacks frequency. However, the effect on headache severity became statistically non-significant when baseline values of headache severity and potential confounders were taken into account. Authors conclude that zinc supplementation was beneficial for migraine attack frequency but not for migraine attack duration and headache daily results.
Expert Review
Conflicts of interest:
None
Take Home Message:
- Inadequate zinc intake may drive migraine frequency.
- Zinc supplementation may enhance the effectiveness of routine migraine treatment in reducing migraine frequency.
Evidence Category:
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X
A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Migraines, characterised by severe headaches, nausea, vomiting, photophobia, and phonophobia affect approximately 10-20% of the global population. The authors refer to observational studies that have identified a moderate rate of zinc deficiency amongst migraine sufferers.
Zinc, an essential trace mineral, may prove beneficial as a supplement to reduce migraine symptoms and frequency possibly due to its effects on the nervous system and its antioxidant and anti-inflammatory capacity..
This double blind randomised clinical trial analysed the effects of 220mg of zinc sulphate (50mg of elemental zinc) combined with a routine migraine treatment versus a control group receiving a placebo and the routine treatment on symptoms of migraine attacks. The study duration was 8 weeks occurring from January 2016 to April 2016. Each group consisted of 40 participants between the ages of 20 and 60 with >5 years of migraines or migraine symptoms.
When compared to the placebo group, zinc supplementation demonstrated:
- A reduction in headache severity (− 1.75 ± 1.79 vs. -0.80 ± 1.57; P = 0.01). This result became statistically non-significant when the analysis was adjusted for potential confounders and baseline values of headache severity.
- A reduction in migraine attacks frequency (− 2.55 ± 4.32 vs. -0.42 ± 4.24; P = 0.02).
Clinical practice applications:
This randomised controlled trial highlights that zinc supplementation combined with routine migraine treatment (200/500 mg sodium valproate (such as Depakin), 50/100 mg sumatriptan, or 1 mg ergotamine) may assist in the reduction of migraine attack frequency amongst migraine sufferers within 8 weeks.
Compliance rate for this study was very high at 100% and there were no adverse effects reported suggesting a potentially safe and convenient treatment for migraine sufferers.
Considerations for future research:
- Further trials with better dietary controls would be useful to eliminate potential confounders.
- Use of CONSORT guidelines for reporting randomised trials would strengthen research reporting.
- Analysis of biomarkers may assist in identifying the mechanisms in which zinc may relieve migraine symptoms..
- Larger randomised controlled trials with increased sample sizes and longer durations are needed in order to definitively determine the effect of zinc supplementation on migraine attacks and any differences between genders.
- Additional studies trialling various zinc dosages and forms may provide insight into an optimal zinc dose and form for migraine attacks.
Abstract
BACKGROUND Observational studies have shown a link between zinc deficiency and migraine headaches. We aimed to examine the effect of zinc supplementation on the characteristics of migraine attacks in patients with migraine. METHODS This randomized clinical trial was conducted on 80 patients with migraine. Patients were randomly assigned to receive either zinc sulfate (220 mg/d zinc sulfate) or placebo (lactose) for 8 weeks. Anthropometric measures, serum zinc concentrations, and characteristics of migraine attacks (headache severity, frequency and duration of migraine attacks, and headache daily results) were assessed at baseline and end of the trial. RESULTS Compared with the placebo, zinc supplementation resulted in a significant reduction in headache severity (- 1.75 ± 1.79 vs. -0.80 ± 1.57; P = 0.01) and migraine attacks frequency (- 2.55 ± 4.32 vs. -0.42 ± 4.24; P = 0.02) in migraine patients. However, the observed reduction for headache severity became statistically non-significant when the analysis was adjusted for potential confounders and baseline values of headache severity. Other characteristics of migraine attacks including the duration of attacks and headache daily results were not altered following zinc supplementation either before or after controlling for covariates. CONCLUSION Zinc supplementation had a beneficial effect on the frequency of migraine attacks in migraine patients. Additional well-designed clinical trials with a long period of intervention and different dosages of zinc are required. TRIAL REGISTRATION CODE IRCT20121216011763N23 at www.irct.ir .