Bone mineral density, vitamin D status, and calcium intake in healthy female university students from different socioeconomic groups in Turkey
Peak bone mass is reached in late adolescence. Low peak bone mass is a well recognized risk factor for osteoporosis later in life. Our data do not support a link between vitamin D status, bone mineral density (BMD), and socioeconomic status (SES). However, there was a marked inadequacy of daily calcium intake and a high presence of osteopenia in females with low SES.
Our aims were to (1) examine the effects of different SES on BMD, vitamin D status, and daily calcium intake and (2) investigate any association between vitamin D status and BMD in female university students.
Subjects and methods
A questionnaire was used to obtain information about SES, daily calcium intake, and physical activity in 138 healthy, female university students (age range 18–22 years). Subjects were stratified into lower, middle, and higher SES according to the educational and occupational levels of their parents. All serum samples were collected in spring for 25-hydroxyvitamin D concentration (25OHD). Lumbar spine and total body BMD was obtained by dual-energy X-ray absorptiometry (DXA) scan (Lunar DPX series). Osteopenia was defined as a BMD between − 1.0 and − 2.5 standard deviations (SDs) below the mean for healthy young adults on lumbar spine DXA.
No significant difference was found between the three socioeconomic groups in terms of serum 25OHD concentration, BMD levels, or BMD Z scores (p > 0.05). Both the daily intake of calcium was significantly lower (p = 0.02), and the frequency of osteopenia was significantly higher in girls with low SES (p = 0.02). There was no correlation between serum 25OHD concentration and calcium intake and BMD values and BMD Z scores (p > 0.05). The most important factor affecting BMD was weight (β = 0.38, p < 0.001).
Low SES may be associated with sub-optimal bone health and predispose to osteopenia in later life, even in female university students.
KeywordsVitamin D Osteopenia Bone mineral density
Compliance with ethical standards
Conflicts of interest
- 10.Brown AJ, Dusso A, Slatopolsky E (1999) Vitamin D. Am J Phys 277(2 Pt 2):F157–F175Google Scholar
- 17.Hollingshead A (1957) Two factor index of social position. Yale Univ. Press, New HeavenGoogle Scholar
- 18.Lewiecki EM, Gordon CM, Baim S, Leonard MB, Bishop NJ, Bianchi ML, Kalkwarf HJ, Langman CB, Plotkin H, Rauch F, Zemel BS, Binkley N, Bilezikian JP, Kendler DL, Hans DB, Silverman S (2008) International Society for Clinical Densitometry 2007 adult and pediatric official positions. Bone 43(6):1115–1121PubMedCrossRefGoogle Scholar
- 21.Committee to Review Dietary Reference Intakes for Vitamin D and Calcium, Food and Nutrition Board, Institute of Medicine (2010) Dietary reference intakes for calcium and vitamin D. National Academy Press, Washington, DCGoogle Scholar
- 22.Turkish Food Composition Database. Gıda, Tarım ve Hayvancılık Bakanlığı www.turkkomp.gov.tr
- 23.Committee PAGA. Physical activity guidelines advisory committee report. 2012. http://www.health.gov/paguidelines/report/. Accessed 01 Dec 2014
- 24.Holick MF, Binkley NC, Bischoff-Ferrari HA, Gordon CM, Hanley DA, Heaney RP, Murad MH, Weaver CM, Endocrine Society (2011) Evaluation, treatment, and prevention of vitamin D deficiency: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab 96(7):1911–1930PubMedCrossRefGoogle Scholar
- 28.Tatsumi Y, Higashiyama A, Kubota Y, Sugiyama D, Nishida Y, Hirata T, Kadota A, Nishimura K, Imano H, Miyamatsu N, Miyamoto Y, Okamura T (2016) Underweight young women without later weight gain are at high risk for osteopenia after midlife: the KOBE study. J Epidemiol 26(11):572–578PubMedCrossRefGoogle Scholar
- 31.Kaehler ST, Baumgartner H, Jeske M, Anliker M, Schennach H, Marschang P, Ratt A, Colvin AC, Falk J, Gasser A, Kirchebner J, Scherer C, Purtscher AE, Griesmacher A, Striessnig J (2012) Prevalence of hypovitaminosis D and folate deficiency in healthy young female Austrian students in a health care profession. Eur J Nutr 51(8):1021–1031PubMedCrossRefGoogle Scholar
- 34.Winzenberg TM, Shaw K, Fryer J, Jones G (2006) Calcium supplementation for improving bone mineral density in children. Cochrane database Syst Rev (2):CD005119Google Scholar
- 35.Closa-Monasterolo R, Zaragoza-Jordana M, Ferré N, Luque V, Grote V, Koletzko B, Verduci E, Vecchi F, Escribano J (2017) Childhood obesity project group. Adequate calcium intake during long periods improves bone mineral density in healthy children. Data from the Childhood Obesity Project. Clin Nutr S0261-5614(17):30102–30104Google Scholar
- 37.Valimaki MJ, Karkkainen M, Lamberg-Allardt C, Laitinen K, Alhava E, Heikkinen J, Impivaara O, Makela P, Palmgren J, Seppannen R, Vuori I, and the Cardiovascular Risk in Young Finns Study Group (1994) Exercise, smoking, and calcium intake during adolescence and early adulthood as determinants of peak bone mass: cardiovascular risk in young Finns study group. BMJ 309:230–235PubMedPubMedCentralCrossRefGoogle Scholar