Bone mineral density, vitamin D status, and calcium intake in healthy female university students from different socioeconomic groups in Turkey.

Unlabelled: 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.

Purpose: 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.

Results: 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).

Conclusions: Low SES may be associated with sub-optimal bone health and predispose to osteopenia in later life, even in female university students.