Table 2.
Characteristics of included studies
| Title | Author | Year | Review type | Included studies | Outcome(s) | Finding(s) |
|---|---|---|---|---|---|---|
| Antioxidant supplements and semen parameters: an evidence-based review. | Ahmadi S, Bashiri R, Ghadiri-Anari A, Nadjarzadeh A. | 2016 | Review | 16 clinical trials | Improving semen parameters such as sperm concentration, motility, morphology, DNA damage, and fertility rate. | Using vitamin C, vitamin E and CoQ10 can improve sperm parameters in infertile men. |
| A review of the potential interaction of selenium and iodine on placental and child health. | Habibi N, Grieger JA, Bianco-Miotto T. | 2020 | Review | 28 clinical trials on selenium | Correlation between selenium and iodine in pregnancy complications due to oxidative stress. | Micronutrient deficiencies in the preconception period affect the health of the placenta. |
| Antioxidant therapy in idiopathic oligoasthenoteratozoospermia | Majzoub A, Agarwal A. | 2017 | Review | 21 clinical trials; Cochrane review of 48 randomized controlled clinical trials; 17 randomized trials; 20 trials. | Finding the rationale and evidence supporting the use of antioxidants in idiopathic oligoasthenoteratozoospermia. | Carnitines, glutathione, vitamins E and C, coenzyme-Q10, N-acetylcysteine, selenium, zinc, folic acid, and lycopene reduce sperm damage induced by oxidative stress. Reviews and meta-analyses analyzed reported an improvement in sperm parameters and birth rates. |
| Antioxidants for female subfertility. | Showell MG, Mackenzie-Proctor R, Jordan V, Hart RJ. | 2017 | Systematic review | 50 Randomized clinical trials | Determine whether oral antioxidant supplement versus placebo, no treatment or standard treatment, or other antioxidants improve fertility outcomes for subfertile women. | Very low-quality evidence shows that taking an antioxidant may provide benefits to subfertile women. |
| Intracellular signalling during female gametogenesis. | (Sobinoff AP, Sutherland JM, Mclaughlin EA. | 2012 | Review | The impact of zinc on oocyte development. | A novel role for the metal ion zinc was proposed in the regulation of meiosis I and meiosis II progression through early meiosis inhibitor (Emi2) and Mos-Mapk signaling for the oocyte development. | |
| Changes in vitamin E levels as a marker of female infertility. | Ashraf, M., Mustansir, F., Baqir, S. M., Alam, F., & Rehman, R. | 2020 | Review | The impact of vitamin E levels of follicular fluid on oocyte competence, embryo development, and pregnancy outcome in patients. | Adequate amount of vitamin E in follicular fluid enhances the possibility of maturation of oocytes. | |
| Diet and fertility: a review | Audrey J. Gaskinks, Sc.D., and Jorge E. Chavarro. | 2017 | Review | Evaluate the effects of diet and antioxidant compounds on fertility. | Antioxidant compounds can support both male and female fertility. | |
| Diet and nutritional factors in male (in)fertility—underestimated factors. |
Kinga Skoracka, Piotr Eder, Liliana Łykowska-Szuber, Agnieszka Dobrowolska and Iwona Krela-Ka´zmierczak. |
2020 | Review | Evaluate the effects of diet and antioxidant compounds on male infertility and semen quality. | Omega-3 fatty acids, vitamin D, E, zinc, selenium, copper, and manganese supplementation can improve semen quality and male fertility. | |
| Dietary requirements of “nutritionally non-essential amino acids” by animals and humans. | Wu, G., Wu, Z., Dai, Z. et al. | 2012 | Review | Needs of experimental evidence to support the assumption of non-essential amino acids. | Glutamine acts a role in gene expression, cell signaling, antioxidative responses, neurotransmission, and immunity. In addition, glutamine is among the main metabolic fuels of the small intestine in maintaining both digestive function and protecting the integrity of the mucosa. | |
| Dietary fatty acids affect semen quality: a review. | V. Esmaeili, A. H. Shahverdi, M. H. Moghadasian and A. R. Alizadeh. | 2015 | Review | 11 clinical trials | Evaluate the effects of Omega-3 fatty acids on semen quality. | Omega-3 fatty acids supplementation can ameliorate the concentration of spermatozoa, percentages of progressively motile and morphologically normal spermatozoa. |
| Dietary supplements for male infertility: a critical evaluation of their composition. | Garolla A, Petre GC, Francini-Pesenti F, De Toni L, Vitagliano A, Di Nisio A, Foresta C. | 2020 | Review | Critical analysis of dietary supplements. | There are nutritional supplements on the Italian market consisting of nutrients with proven efficacy, but also of nutrients whose benefits have not been scientifically proven and which may even be harmful. | |
| Effectiveness of omega-3 fatty acid for polycystic ovary syndrome: a systematic review and meta-analysis. | Kailin Yang, Liuting Zeng , Tingting Bao and Jinwen Ge. | 2018 | Review | 15 clinical trials | Evaluate the effects of omega-3 fatty acids in PCOS-related infertility. | Omega-3 fatty acids acid may be recommended for the treatment of PCOS with insulin resistance. |
| Effects of zinc deficiency on impaired spermatogenesis and male infertility: the role of oxidative stress, inflammation, and apoptosis. | Beigi Harchegani A, Dahan H, Tahmasbpour E, Bakhtiari Kaboutaraki H, Shahriary A. | 2020 | Review | To discuss the molecular mechanisms by which zinc is involved in male reproduction. | Zinc deficiency is implicated in spermatogenesis disorders and male infertility. It induces oxidative stress with consequent damage to Leydig cells, alteration of steroidogenesis, accumulation of leucocytes, and inflammation. It may be useful to screen all infertile men for this defect. | |
| Empirical medical therapy in idiopathic male infertility: promise or panacea? | Jung JH, Seo JT. | 2014 | Review | Evaluate the literature regarding the most common empirical medical treatments (hormonal treatment and antioxidant supplementation) in idiopathic male infertility. | Empirical medical treatments appear to have a positive effect on male fertility, but standardized protocols need to be established in order to implement them effectively. | |
| Evidence for a manifold role of selenium in infertility. | Mintziori G, Mousiolis A, Duntas LH, Goulis DG. | 2019 | Review | Evaluate the role of selenium in male and female infertility. | Studies are needed to prove the benefits of Selenium supplementation in men and women. | |
| Glutamine: metabolism and immune function, supplementation and clinical translation. | Cruzat V, Rogero M.M, Keane K.N, Curi R, Newsholme P. | 2018 | Review | Role of glutamine in cells of the immune system; glutamine metabolism and action. | Immune cells and their functions are largely dependent on the availability of glutamine. During catabolic/hypercatabolic situations glutamine can become essential for metabolic function. | |
| Immunological role of vitamin D at the maternal-fetal interface. | Tamblyn JA, Hewison M, Wagner CL, Bulmer JN, Kilby MD. | Review | Evaluate the effects of vitamin D during pregnancy. | Gain of responses and modulation of T-lymphocytes to suppress inflammation and promote tolerance mediated through vitamin D actions. | ||
| Impact of arginine nutrition and metabolism during pregnancy on offspring outcomes. | Hsu CN, Tain YL. | 2019 | Review | Analysis of the influence of arginine during pregnancy, the consequences of its deficiency, and its role in the prevention of NCDs. | Arginine plays an important role both during pregnancy and in the long-term health of the unborn child. However, in order to best influence the metabolic pathways of this amino acid further studies are needed Currently, the evidence supporting the role of micronutrients and vitamins in the prevention of pre-eclampsia is not strong enough to justify their systematic use. | |
| Interactions between estrogen and 1α,25(OH)2-vitamin D3 signalling and their roles in spermatogenesis and spermatozoa functions. | Ana Paula Zanatta, Vanessa Brouard , Camille Gautier , Renata Goncalves, Hélène Bouraïma-Lelong , Fátima Regina Mena Barreto Silva and Christelle Delalande. | 2017 | Review | Understanding molecular mechanism and signaling pathways of VD in spermatogenesis. | VD plays a key role in spermatogenesis through genomic- and non-genomic pathways. | |
| Monosodium glutamate (MSG)-induced male reproductive dysfunction: a mini review. | Kayode OT, Rotimi DE, Kayode A, Olaolu TD, Adeyemi OS. | 2020 | Review | Monosodium glutamate (MSG) has been found to be potent in articulating reproductive abnormalities in males. | The different mechanisms involved include spermatogenic alteration, histological alteration, and hormonal imbalances. | |
| MOSH syndrome (male obesity secondary hypogonadism): clinical assessment and possible therapeutic approaches. | Antonino De Lorenzo, Annalisa Noce, Eleonora Moriconi, Tiziana Rampello,Giulia Marrone, Nicola Di Daniele,and Valentina Rovella. | 2018 | Review | Potential role of omega-3 fatty acids in male obesity secondary hypogonadism. | Omega-3 fatty acids supplementation can support the restore of the balanced male hormone axis. | |
| Multiple micronutrient supplementation and birth outcomes: the potential importance of selenium. | Perkins AV, Vanderlelie JJ. | 2016 | Review | Examine the use of micronutrients during pregnancy and current recommendations for these products. | A beneficial effect in pregnancy has been shown e reduce the risk of preeclampsia and preterm labor, especially in overweight and obese women. | |
| Novel insights on the role of nitric oxide in the ovary: a review of the literature. | Budani MC, Tiboni GM. | 2021 | Review | Analysis of data on the role of arginine at the ovarian level. | Arginine plays an important role in steroidogenesis and folliculogenesis, as well as being crucial in oocyte competence. | |
| Nutrient supplementation: improving male fertility fourfold. | Mora-Esteves C, Shin D. | 2013 | Review | 34 randomized controlled trials | Evaluate the improvement of outcomes of assisted reproduction and the action of different types of antioxidants. | A definitive conclusion cannot be drawn because of the heterogeneous literature. |
| Nutritional approach to preeclampsia prevention. | Achamrah N, Ditisheim A. | 2018 | Review | To analyze the latest data on the nutritional approach to pre-eclampsia. | Currently, the evidence supporting the role of micronutrients and vitamins in the prevention of pre-eclampsia is not strong enough to justify their systematic use. | |
| Regulation of protein metabolism by glutamine: implications for nutrition and health. | Xi P, Jiang Z, Zheng C, Yingcai , Wu G. | 2011 | review | Evaluation of the utility of glutamine supplementation in enteral diets or parenteral solutions to improve nitrogen balance with glutamine deficiency. | Glutamine could stimulate protein synthesis and inhibit proteolysis in skeletal muscle. glutamine concentrations show marked reductions in response to infection, sepsis, severe burns, cancer, and other pathological factors. | |
| Role of dietary amino acids and nutrient sensing system in pregnancy associated disorders. | Hussain T, Tan B, Murtaza G, Metwally E, Yang H, Kalhoro MS, Kalhoro DH, Chughtai MI, Yin Y. | 2020 | Review | Exploring the importance of dietary amino acids and their metabolic pathways on pregnancy. | Amino acid supplementation has a positive impact on fertility, improving many aspects of pregnancy and fetal life. | |
| Role of oxidative stress in female reproduction. | Agarwal A, Gupta S, Sharma RK. | 2005 | Review | Role of nitric oxide species in female reproduction, interaction between cytokines and oxidative stress in the etiology of female reproductive disorders. | Combination of intervention strategy of vitamin E and vitamin C supplementation in preventing preeclampsia are highlighted. Antioxidants are powerful and there are few trials investigating antioxidant supplementation in female reproduction. However, randomized controlled trials with sufficient power are necessary to prove the efficacy. | |
| Role of selenium and selenoproteins in male reproductive function: a review of past and present evidences. | Qazi IH, Angel C, Yang H, et al. | 2019 | Review | 8 human studies | Evaluation of selenoproteins in male reproduction. | No definitive conclusions on their effects were identified. |
| Selenium, selenoproteins, and female reproduction: a review. | Qazi IH, Angel C, Yang H, et al. | 2018 | Review | Biological functions of Selenium and selenoproteins and the relationship between Selenium and female reproductive function. | Studies not yet sufficient to draw valid conclusions. | |
| Strengthening the immunity of the Swiss population with micronutrients: a narrative review and call for action. | Berger MM, Herter-Aeberli I, Zimmermann MB, Spieldenner J, Eggersdorfer M. | 2021 | Review | Evaluate the effects of micronutrients, such as Vitamin D, Omega-3 FAs, Vitamin C, Iron for optimal immune function and prevention of respiratory tract infections. | Strong relationships between micronutrient and n-3 PUFA status and immune function. | |
| Systematic review of antioxidant types and doses in male infertility: Benefits on semen parameters, advanced sperm function, assisted reproduction and live-birth rate. | Majzoub A, Agarwal A. | 2018 | Systematic review | 19 randomized clinical trials; 10 prospective studies | Evaluation of the effect on male fertility of oral antioxidant supplementation. | 26 studies showed a significant effect on baseline semen parameters, advanced sperm function, outcomes of assisted reproductive therapy, and birth rate. |
| The excessive use of antioxidant therapy: A possible cause of male infertility? | Henkel R, Sandhu IS, Agarwal A. | 2019 | Review | 8 clinical trials | Establish the presence of benefits and risks of antioxidant therapy for male infertility. | The use of antioxidants must be considered with caution as in addition to the beneficial effects they have side effects. |
| The role of over-the-counter supplements for the treatment of male infertility--fact or fiction? | Ko EY, Sabanegh ES Jr. | 2012 | Review | 22 clinical trials | Evaluate the effects of micronutrients on male fertility. | No definitive conclusions on their effects were identified and the dosage could not be identified. |
| The role of selenium in human conception and pregnancy. | Pieczyńska J, Grajeta H. | 2015 | Review | 11 clinical trials | Demonstrate the correlations with problems related to procreation. | Selenium supplementation in case of deficiencies is important, both for women and men. |
| Vitamin C and immune function. | Carr A.C, Maggini S. | 2017 | Review | Role of vitamin c in the modulation of the immune system. | Vitamin C has a potent antioxidant role against ROS; its action as a cofactor for numerous biosynthetic and gene regulatory enzymes plays a key role in its immunomodulatory effects. | |
| Vitamin C as an antioxidant supplement in women's health: a myth in need of urgent burial. | Talaulikar VS, Manyonda IT. | 2011 | Review | Vitamin supplements with antioxidant properties, such as vitamins C, could also prevent pre-eclampsia and improve pregnancy health. | Despite the role of oxidative stress in the pathophysiology of pre-eclampsia and the possibility of improvement of the disease by an antioxidant administered at the right time and in the correct dosage, there is no strong evidence for great benefits. | |
| Vitamin D and aspects of female fertility. | Nick Voulgaris, Labrini Papanastasiou, George Piaditis, Anna Angelousi, Gregory Kaltsas, George Mastorakos, Eva Kassi. | 2017 | Review | 15 clinical trials | Evaluate the effects of VD supplementation in PCOS, Endometriosis related female infertility, and for IVF and implantation. | VD can support female fertility in PCOS, endometriosis, and IVF. |
| Vitamin D and health - the missing vitamin in humans. | Chang SW, Lee HC. | 2019 | Review | Determine the lacking effects of Vitamin D on human health. | Appropriate vitamin D supplementation is recommended to obtain optimal plasma concentration. | |
| Vitamin D and obesity: two interacting players in the field of infertility. | Julia K. Bosdou, Eirini Konstantinidou, Panagiotis Anagnostis, Efstratios M. Kolibianakis, and Dimitrios G. Goulis. | 2019 | Review | 40 clinical trials | Evaluate the effects of VD supplementation in male infertile subjects. | VD can support spermatogenesis and male fertility in both healthy and obese men. |
| Vitamin D in endometriosis: a causative or confounding factor? | Sayegh L, Fuleihan Gel-H, Nassar AH. | 2014 | Review | 6 clinical trials | Evaluate the effects of VD in endometriosis-related infertility. | VD can acts as an immunomodulator and anti-inflammatory agent, in the pathogenesis and treatment of endometriosis. |
| Vitamin D metabolism and guidelines for vitamin D supplementation. | Ramasamy I. | 2020 | Review | Define the proper VD supplementation and determine the correct serological values for VD. | Supplementation of VD should be included from 400 to 1000 IU/d (10–25 μg/day) | |
| Vitamin D and its role during pregnancy in attaining optimal health of mother and fetus. | Wagner CL, Taylor SN, Dawodu A, Johnson DD, Hollis BW. | 2012 | Review | 2 clinical trials | Overview of vitamin metabolism, states of deficiency. | Vitamin D supplementation is necessary to achieve an optimal 1,25(OH)D3 levels in pregnancy. |
DNA, deoxyribonucleic acid; PCOS, polycystic ovary syndrome; NCD, non-communicable disorders; VD, vitamin D; IVF, in vitro fertilization