The objective of this observational study performed in USA «Haagensen AL, Feldman HA, Ringelheim J ym. Low pre...»1 was to determine whether patients with anorexia nervosa (AN) are more compliant with supplementation and have a lower prevalence of vitamin D deficiency than healthy controls. Fifty adolescents with AN (mean age 18.4 ± 2.7years, BMI 18.0 ± 1.6 kg/m2) and 200 healthy girls (mean age 14.9 ± 2.0 years, BMI 24.2 ± 6.0 kg/m2) underwent vitamin D screening. Fifty adolescents with AN and 200 controls were compared using anthropometric and lifestyle data, serum 25-hydroxyvitamin D (25OHD) and parathyroid hormone (PTH) concentrations, and prevalence of vitamin D deficiency. The prevalence of deficiency (< 20 ng/mL) was 2 % in the AN group vs. 24 % among controls (p = 0.003). 25OHD was similar among white participants with AN and white controls (39.5 vs. 36.0 ng/mL, p = 0.20), but higher than in non-white controls (20.6 ng/mL). Significantly more girls with AN reported vitamin D supplementation (86 %) than the full control (14 %) or white subgroup (27 %) (p < 0.001). Participants with AN had lower PTH concentrations than controls, (27.8 vs. 47.4 pg/mL, p = 0.009), a trend that lost significance after age and race adjustment (41.7 pg/mL, p = 0.12). Compared to healthy controls, adolescents with AN had a lower prevalence of vitamin D deficiency and PTH concentration. However, 25OHD and PTH concentrations were similar after adjustment for race and age. The trend of lower PTH levels in adolescents with AN, accompanied by exceptional compliance with supplementation, may have bone health implications for these patients.
A prospective cohort study performed in the USA «Misra M, Tsai P, Anderson EJ ym. Nutrient intake i...»2 compared the nutrients intake in community-dwelling adolescent females (n = 39, age 15.9 ± 0.3 years) with AN with age-matched control subjects (n = 39, age 15.0 ± 0.3 years). The mean (± SEM) duration of illness was 11.3 ± 1.9 months in the AN group, Although there was no significant difference between the two groups in dietary intake of calcium, zinc and iron, the group with AN had an overall greater intake of vitamins A, D K and most of the B vitamins. Significant more girls with AN met the Dietary Reference intake (DRI) for calcium (30.0 % vs 59.0 %, p < 0.01) and vitamin D (76.9 % vs 50.0 %, p < 0.05), which was attributed to a greater use of dietary supplement in this group. Despite this, however, the lumbar spine BMD Z-scores of this group remained low, and did not differ between the AN group who met or did not met the DRI for calcium and vitamin D (data not shown).