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Many women with PCOS have been found to have an unbalanced diet and deficiencies in essential nutrients. This study aimed to assess the levels of folate and vitamin B12 (B12) and their relationship with metabolic factors in women with PCOS. Anthropometric, clinical, and genetic analyses were conducted to evaluate markers related to one-carbon metabolism in women with PCOS and in a control group. The PCOS group had a higher BMI and HOMA-IR (1.7 vs. 3.1; p &lt; 0.0001). HDL cholesterol levels were 23% lower and triglyceride levels were 74% higher in women with PCOS. Although there were no significant differences in folate and B12 levels between the PCOS and control groups, over 60% of women with PCOS had low B12 levels (&lt;300 pg\/mL) and high homocysteine levels. In addition, the MTHFR A1298C and C677T polymorphisms were not associated with PCOS. Moreover, erythrocyte folate levels were positively correlated with fasting glucose, triglycerides, and free androgen index, and negatively correlated with SHBG and LH levels. These results suggest that B vitamins may be associated with the metabolic phenotype in PCOS. This study emphasizes the potential link between folate, vitamin B12, and metabolic and hormonal outcomes in women with PCOS.<\/jats:p>","DOI":"10.3390\/nu16121937","type":"journal-article","created":{"date-parts":[[2024,6,19]],"date-time":"2024-06-19T04:21:28Z","timestamp":1718770888000},"page":"1937","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["Folate and Vitamin B12 Levels in Chilean Women with PCOS and Their Association with Metabolic Outcomes"],"prefix":"10.3390","volume":"16","author":[{"given":"Mat\u00edas","family":"Carrasco-Cabezas","sequence":"first","affiliation":[{"name":"Laboratory of Chemical Carcinogenesis and Pharmacogenetics, Faculty of Medicine, Universidad de Chile, Santiago 8320000, Chile"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9114-8243","authenticated-orcid":false,"given":"Ta\u00eds Silveira","family":"Assmann","sequence":"additional","affiliation":[{"name":"Graduate Program in Medical Sciences, Endocrinology, Department of Internal Medicine, Faculty of Medicine, Federal University of Rio Grande do Sul, Porto Alegre 90035-003, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Paz","family":"Mart\u00ednez","sequence":"additional","affiliation":[{"name":"Laboratory of Endocrinology and Metabolism, Department of Internal Medicine, West Division, Faculty of Medicine, Universidad de Chile, Santiago 8320000, Chile"},{"name":"Health Sciences Institute, Universidad de O\u2019Higgins, Rancagua 3070000, Chile"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9525-389X","authenticated-orcid":false,"given":"Leslie","family":"Cerpa","sequence":"additional","affiliation":[{"name":"Laboratory of Chemical Carcinogenesis and Pharmacogenetics, Faculty of Medicine, Universidad de Chile, Santiago 8320000, Chile"},{"name":"Latin American Network for Implementation and Validation of Clinical Pharmacogenomics Guidelines (RELIVAF-CYTED), Santiago 8320000, Chile"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Susan","family":"Calfunao","sequence":"additional","affiliation":[{"name":"Laboratory of Chemical Carcinogenesis and Pharmacogenetics, Faculty of Medicine, Universidad de Chile, Santiago 8320000, Chile"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"B\u00e1rbara","family":"Echibur\u00fa","sequence":"additional","affiliation":[{"name":"Laboratory of Endocrinology and Metabolism, Department of Internal Medicine, West Division, Faculty of Medicine, Universidad de Chile, Santiago 8320000, Chile"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3872-0217","authenticated-orcid":false,"given":"Manuel","family":"Maliqueo","sequence":"additional","affiliation":[{"name":"Laboratory of Endocrinology and Metabolism, Department of Internal Medicine, West Division, Faculty of Medicine, Universidad de Chile, Santiago 8320000, Chile"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nicol\u00e1s","family":"Crisosto","sequence":"additional","affiliation":[{"name":"Laboratory of Endocrinology and Metabolism, Department of Internal Medicine, West Division, Faculty of Medicine, Universidad de Chile, Santiago 8320000, Chile"},{"name":"Endocrinology Unit, Department of Medicine, Cl\u00ednica Alemana de Santiago, Faculty of Medicine, Universidad del Desarrollo, Santiago 7650568, Chile"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Francisca","family":"Salas-P\u00e9rez","sequence":"additional","affiliation":[{"name":"Health Sciences Institute, Universidad de O\u2019Higgins, Rancagua 3070000, Chile"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,6,19]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"767","DOI":"10.1016\/j.fertnstert.2023.07.025","article-title":"Recommendations from the 2023 International Evidence-Based Guideline for the Assessment and Management of Polycystic Ovary Syndrome","volume":"120","author":"Teede","year":"2023","journal-title":"Fertil. 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