{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,28]],"date-time":"2026-10-28T16:50:26Z","timestamp":1793206226482,"version":"4.5.0"},"reference-count":45,"publisher":"BMJ","issue":"3","license":[{"start":{"date-parts":[[2021,3,22]],"date-time":"2021-03-22T00:00:00Z","timestamp":1616371200000},"content-version":"unspecified","delay-in-days":21,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"funder":[{"name":"Danone Institute China Diet Nutrition Research & Communication Grant","award":["DIC2015-05"],"award-info":[{"award-number":["DIC2015-05"]}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["41871360"],"award-info":[{"award-number":["41871360"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"name":"National Key Research and Development Program of China","award":["2018YFC1004303"],"award-info":[{"award-number":["2018YFC1004303"]}]},{"name":"National Health Commission Key Laboratory of Birth Defects Prevention, Henan Province","award":["ZD202002"],"award-info":[{"award-number":["ZD202002"]}]}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open"],"accepted":{"date-parts":[[2021,3,4]]},"published-print":{"date-parts":[[2021,3]]},"abstract":"<jats:sec>\n                    <jats:title>Objective<\/jats:title>\n                    <jats:p>To explore the association between socioeconomic status (SES) and vitamin D deficiency\/insufficiency of women of childbearing age in rural northern China.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Design<\/jats:title>\n                    <jats:p>A population-based, case\u2013control study was conducted.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Setting<\/jats:title>\n                    <jats:p>Four counties of Henan Province, China from 2009 to 2010.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Participants<\/jats:title>\n                    <jats:p>1151 non-pregnant healthy women between 18 and 40 years old.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Primary and secondary outcome measures<\/jats:title>\n                    <jats:p>Serum 25-hydroxyvitamin D (25(OH)D) levels were measured using high-performance liquid chromatography-tandem mass spectrometry. Vitamin D insufficiency was defined as serum 25(OH)D \u226520\u2009ng\/mL and &lt;30\u2009ng\/mL, deficiency as \u226510\u2009ng\/mL and &lt;20\u2009ng\/mL, and severe deficiency as &lt;10\u2009ng\/mL. SES was measured separately by women\u2019s and their husbands\u2019 education level and occupation, household income and expenditure, as well as aggregately by SES index constructed with principal component analysis.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>The median serum 25(OH)D level was 20.90 (13.60\u201334.60)\u2009ng\/mL, and the prevalence of vitamin D insufficiency, deficiency and severe deficiency was 20.16%, 31.80% and 15.99%, respectively. After adjustment, household annual income &lt;\u00a510\u2009000 was associated with increased risk of vitamin D insufficiency (adjusted OR (aOR): 2.10, 95%\u2009CI 1.41 to 3.14), deficiency (aOR: 1.58, 95%\u2009CI 1.09 to 2.29) and severe deficiency (aOR: 2.79, 95%\u2009CI 1.78 to 4.38); inadequate household income for expenditure was associated with elevated risk of vitamin D insufficiency (aOR: 1.66, 95%\u2009CI 1.08 to 2.54) and deficiency (aOR: 1.81, 95%\u2009CI 1.26 to 2.62); low SES index was associated with elevated risk of vitamin D insufficiency (aOR: 2.40, 95%\u2009CI 1.52 to 3.80) and deficiency (aOR: 1.64, 95%\u2009CI 1.08 to 2.50); and both middle and low SES index were associated with increased risk of vitamin D severe deficiency (aOR: 1.70, 95%\u2009CI 1.02 to 2.84; aOR: 2.45, 95%\u2009CI 1.45 to 4.14).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Lower SES was associated with higher risk of vitamin D deficiency\/insufficiency in women of childbearing age in rural northern China. More should be done to explore potential mechanisms and to narrow down SES inequalities in vitamin D status.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1136\/bmjopen-2020-042227","type":"journal-article","created":{"date-parts":[[2021,3,22]],"date-time":"2021-03-22T13:15:24Z","timestamp":1616418924000},"page":"e042227","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":39,"title":["Socioeconomic status and vitamin D deficiency among women of childbearing age: a population-based, case\u2013control study in rural northern China"],"prefix":"10.1136","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1874-5900","authenticated-orcid":false,"given":"Shiqi","family":"Lin","sequence":"first","affiliation":[{"name":"Institute of Population Research\/China Center on Population Health and Development, Peking University, Beijing, 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