Does low serum 25 OH vitamin D interact with very strenuous physical activity, facilitating development of rhabdomyolysis?

Abstract Background: Modifiable lifestyle factors and body composition can affect the attainment of peak bone mass during childhood. This study performed a cross-sectional analysis of the determinants of bone health among pre-adolescent Malaysian children with habitually low calcium intakes and vitamin D status in Kuala Lumpur (PREBONE-Kids Study). Methods: Body composition, bone mineral density (BMD), and bone mineral content (BMC) at the lumbar spine (LS) and total body (TB) were assessed using dual-energy X-ray absorptiometry (DXA). Calcium intake was assessed using 1-week diet history, MET (metabolic equivalent of task) score using cPAQ questionnaire, and serum 25(OH) vitamin D using LC-MS/MS. Results: The mean calcium intake was 348.8 ± 180.1 mg/day and mean serum 25-OH vitamin D level was 43.9 ± 14.5nmol/L. In boys, lean mass (LM) was significantly associated with LSBMC (β = 0.539, p<0.001), LSBMD (β=0.607, p<0.001), TBBMC (β=0.675, p<0.001) and TBBMD (β= 0.481, p<0.01). Height was significantly associated with LSBMC (β =0.346, p<0.001) and TBBMC (β =0.282, p<0.001) while fat mass (FM) (β=0.261, p=0.034) and MET score (β =0.163, p=0.026) were significant predictors of TBBMD. Among girls, LM was significantly associated with LSBMC (β = 0.620, p<0.001), LSBMD (β=0.700, p<0.001), TBBMC (β=0.542, p<0.001) and TBBMD (β= 0.747, p<0.001). Calcium intake was a significant predictor of LSBMC (β=0.102, p=0.034), TBBMC (β=0.122, p<0.001) and TBBMD (β=0.196, p=0.002) in girls. Lean mass (LM) was weakly correlated with MET scores (r = 0.205, p = 0.001) but not protein (r = 0.055, p = 0.393) or energy intake (r = 0.101, p = 0.117). MET score (β = 0.207, p = 0.043) was a significant predictor of LM in boys but no factor was found to predict LM in girls. Conclusion: LM is the major determinant of BMC and BMD among pre-adolescent Malaysian children and physical activity is a significant predictor of LM in boys. Encouraging physical activity, calcium intake and optimum diets that build lean body mass should be the focus for developing public health guidance to ensure optimal bone health status during rapid growth.

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Serum concentrations of 25-OH vitamin D in patients with systemic lupus erythematosus (SLE) are inversely related to disease activity: is it time to routinely supplement patients with SLE with vitamin D?: Table 1

Annals of the Rheumatic Diseases ◽

10.1136/ard.2009.120329 ◽

2010 ◽

Vol 69 (6) ◽

pp. 1155-1157 ◽

Cited By ~ 187

Author(s):

H Amital ◽

Z Szekanecz ◽

G Szücs ◽

K Dankó ◽

E Nagy ◽

...

Keyword(s):

Vitamin D ◽

Disease Activity ◽

Lupus Erythematosus ◽

Serum Vitamin ◽

Serum Concentrations ◽

Systemic Lupus ◽

Serum Vitamin D ◽

Z Scores ◽

25 Oh Vitamin D ◽

Low Serum

BackgroundLow serum vitamin D concentrations have been reported in several autoimmune disorders.ObjectiveTo assess whether low serum vitamin D concentrations are related to disease activity of patients with systemic lupus erythematosus (SLE).Methods378 patients from several European and Israeli cohorts were pooled and their disease activity was measured by two different methods: 278 patients had SLE disease activity-2000 (SLEDAI-2K) scores and 100 patients had European Consensus Lupus Activity Measurement (ECLAM) scores. In order to combine the two systems the scores were converted into standardised values (z-scores), enabling univariate summary statistics for the two variables (SLEDAI-2K and ECLAM). The commercial kit, LIAISON 25-OH vitamin D assay (310900-Diasorin) was used to measure serum concentration of 25-OH vitamin D in 378 patients with SLE.ResultsA significant negative correlation was demonstrated between the serum concentration of vitamin D and the standardised values (z-scores) of disease activity scores as measured by the SLEDAI-2K and ECLAM scales (Pearson's correlation coefficient r=−0.12, p=0.018).ConclusionsIn a cohort of patients with SLE originating from Israel and Europe vitamin D serum concentrations were found to be inversely related to disease activity.

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