Journal of Clinical Medicine Research, ISSN 1918-3003 print, 1918-3011 online, Open Access
Article copyright, the authors; Journal compilation copyright, J Clin Med Res and Elmer Press Inc
Journal website http://www.jocmr.org

Original Article

Volume 10, Number 1, January 2018, pages 13-21


The Effect of Ongoing Vitamin D and Low-Fat Milk Intake on Bone Metabolism in Female High-School Endurance Runners

Figure

Figure 1.
Figure 1. Study flow diagram.

Tables

Table 1. Subject Characteristics
 
GroupBaseline3 months6 monthsP
TimeGroupTime × group
Values are represented as mean ± SD. Differences in time (baseline, 3 months, and 6 months) and group (MKD and CON) were evaluated with repeated two-way ANOVAs for subject characteristics. Because fat mass and fat-free mass (FFM) were measured in before and after the 6-month trial period only, the values in 3 months were not measured (-). MKD: vitamin D supplement + low-fat milk group; CON: control group.
Height (cm)MKD158.9 ± 4.2159.0 ± 4.4159.3 ± 4.3< 0.01n.sn.s
CON158.3 ± 5.0158.5 ± 5.0158.9 ± 5.0
Weight (kg)MKD47.3 ± 3.348.5 ± 2.849.3 ± 2.8< 0.01n.sn.s
CON45.3 ± 3.246.8 ± 3.247.6 ± 3.6
BMI (kg/m2)MKD18.7 ± 1.519.2 ± 1.419.5 ± 1.3< 0.01n.sn.s
CON18.1 ± 1.118.7 ± 1.518.9 ± 1.7
Fat mass (%)MKD19.6 ± 5.3-21.8 ± 5.2< 0.01n.sn.s
CON17.9 ± 4.8-21.0 ± 5.6
Appendicular FFM (kg)MKD16.1 ± 1.3-16.6 ± 1.4< 0.01n.sn.s
CON15.7 ± 1.3-16.1 ± 1.2
Running distance (km/month)MKD187.8 ± 88.3215.5 ± 117.7179.4 ± 85.2n.s0.03n.s
CON124.5 ± 70.7103.9 ± 73.9106.7 ± 61.0
Frequency of menses (time/year)MKD11.1 ± 2.211.8 ± 3.312.5 ± 2.9n.s0.04n.s
CON6.8 ± 5.38.2 ± 5.77.7 ± 5.1

 

Table 2. Changes in BMD
 
GroupBaseline6 monthsP
TimeGroupTime × group
Values are represented as mean ± SD. Differences in time (baseline, 3 months, and 6 months) and group (MKD and CON) were evaluated with repeated two-way ANOVAs for BMD. TBLH: total bone less head; MKD: vitamin D supplement + low-fat milk group; CON: control group.
Arms BMD (g/cm2)MKD0.838 ± 0.0630.858 ± 0.051< 0.01n.sn.s
CON0.818 ± 0.0610.828 ± 0.051
Legs BMD (g/cm2)MKD1.217 ± 0.0641.230 ± 0.061< 0.01n.sn.s
CON1.199 ± 0.0771.212 ± 0.072
Pelvic BMD (g/cm2)MKD1.068 ± 0.0821.086 ± 0.076< 0.01n.sn.s
CON1.051 ± 0.0791.077 ± 0.075
Spine BMD (g/cm2)MKD0.967 ± 0.0930.999 ± 0.098< 0.01n.sn.s
CON0.981 ± 0.0731.014 ± 0.069
TBLH BMD (g/cm2)MKD0.992 ± 0.0541.002 ± 0.050< 0.01n.sn.s
CON0.978 ± 0.0590.991 ± 0.050

 

Table 3. Changes in 25(OH)D, PTH, TNF-α, and Bone Metabolism Marker Concentrations
 
GroupBaseline3 months6 monthsP
TimeGroupTime × group
Values are represented as mean ± SD. Differences in time (baseline, 3 months, and 6 months) and group (MKD and CON) were evaluated with repeated two-way ANOVAs for biomarkers. *P < 0.05 vs. CON, †P < 0.05, ††P < 0.01 vs. Baseline. BAP/CTX: bone formation to resorption ratio; MKD: vitamin D supplement + low-fat milk group; CON: control group.
25(OH)D (ng/mL)MKD31.8 ± 6.531.8 ± 5.030.2 ± 3.8< 0.01n.s< 0.01
CON34.7 ± 8.228.0 ± 7.1††27.9 ± 5.3††
PTH (pg/mL)MKD33.9 ± 10.029.2 ± 7.336.9 ± 11.2< 0.01n.s0.06
CON30.0 ± 8.532.0 ± 6.640.5 ± 8.7
TNF-α (pg/mL)MKD1.08 ± 0.28*0.87 ± 0.260.83 ± 0.30†n.sn.s0.04
CON0.71 ± 0.380.85 ± 0.290.71 ± 0.34
CTX (ng/mL)MKD0.66 ± 0.190.54 ± 0.180.55 ± 0.180.04n.sn.s
CON0.85 ± 0.230.70 ± 0.250.76 ± 0.48
BAP (µg/L)MKD15.7 ± 5.515.3 ± 4.116.1 ± 3.3n.sn.sn.s
CON17.5 ± 9.517.7 ± 11.118.2 ± 10.8
BAP/CTXMKD24.8 ± 10.431.9 ± 17.633.5 ± 16.4< 0.01n.sn.s
CON20.2 ± 7.324.7 ± 7.424.8 ± 6.8

 

Table 4. Effect of Vitamin D Supplementation and Low-Fat Milk Intake on Each Biomarker
 
Baseline to 3 monthsBaseline to 6 months
CON (n = 10)MKD (n = 10)PCON (n = 10)MKD (n = 10)P
Values are represented as mean ± SE. The change in concentration of each biomarker in both groups was compared after each biomarker was adjusted for Baseline values, frequency of menses, and running distance, respectively. Model 1: baseline value. Model 2: baseline value, frequency of menses (baseline value). Model 3: baseline value, frequency of menses (baseline value), running distance (baseline value). MKD: vitamin D supplement + low-fat milk group; CON: control group.
25(OH)D (ng/mL)
  Model 1-6.33 ± 0.76-0.32 ± 0.76< 0.01-6.12 ± 0.78-2.21 ± 0.78< 0.01
  Model 2-6.17 ± 0.83-0.48 ± 0.83< 0.01-5.87 ± 0.85-2.45 ± 0.850.02
  Model 3-6.19 ± 0.96-0.46 ± 0.96< 0.01-5.46 ± 0.95-2.87 ± 0.950.11
PTH (pg/mL)
  Model 11.17 ± 1.50-3.87 ± 1.500.039.91 ± 2.533.59 ± 2.530.10
  Model 22.01 ± 1.53-4.71 ± 1.530.019.67 ± 2.773.83 ± 2.770.18
  Model 31.63 ± 1.65-4.33 ± 1.650.047.32 ± 2.436.18± 2.430.77
TNF-α (pg/mL)
  Model 10.03 ± 0.08-0.11 ± 0.080.25-0.07 ± 0.08-0.19 ± 0.080.36
  Model 20.04 ± 0.10-0.12 ± 0.100.35-0.10 ± 0.10-0.16 ± 0.100.71
  Model 3-0.03 ± 0.08-0.05 ± 0.080.94-0.10 ± 0.11-0.16 ± 0.110.77
CTX (ng/mL)
  Model 1-0.13 ± 0.04-0.13 ± 0.040.95-0.10 ± 0.09-0.09 ± 0.090.92
  Model 2-0.15 ± 0.04-0.12 ± 0.040.60-0.14 ± 0.09-0.05 ± 0.090.50
  Model 3-0.14 ± 0.04-0.13 ± 0.040.86-0.15 ± 0.09-0.04 ± 0.090.44
BAP (µg/L)
  Model 10.31 ± 1.58-0.53 ± 1.580.710.85 ± 1.390.33 ± 1.390.80
  Model 2-0.18 ± 1.72-0.04 ± 1.720.960.90 ± 1.540.29 ± 1.540.80
  Model 30.25 ± 2.01-0.47 ± 1.960.821.05 ± 1.770.13 ± 1.770.75

 

Table 5. The Correlation Between 25(OH)D or PTH Concentrations and Bone Metabolism Markers With Adjustment for Frequency of Menses
 
CTX (ng/mL)BAP/CTX
Baseline3 months6 monthsBaseline3 months6 months
rPrPrPrPrPrP
Pooled analysis by partial correlation coefficient. Values are r and P values.
25(OH)D (ng/mL)
  Baseline-0.61< 0.01----0.310.19----
  3 months---0.540.02----0.590.01--
  6 months-----0.530.02----0.560.01
PTH (pg/mL)
  Baseline0.200.42-----0.160.50----
  3 months--0.63< 0.01-----0.590.01--
  6 months----0.520.02-----0.58< 0.01