Table 1 Characteristics of the study participants
From: Dietary supplement use in elementary school children: a Japanese web-based survey
| Â | All children | |
|---|---|---|
n | (%) | |
Grade | ||
 1 | 661 | (13.4) |
 2 | 667 | (13.5) |
 3 | 832 | (16.9) |
 4 | 865 | (17.5) |
 5 | 912 | (18.5) |
 6 | 996 | (20.2) |
Sex | ||
 Male | 2529 | (51.3) |
 Female | 2404 | (48.7) |
BMI categorya | ||
 Underweight | 713 | (14.5) |
 Normal-weight | 3119 | (63.2) |
 Overweight | 1101 | (22.3) |
Frequency of sports participation | ||
 Never | 1249 | (25.3) |
 Once a week | 841 | (17.0) |
 2–3 times/week | 1825 | (37.0) |
 4–6 times/week | 623 | (12.6) |
 Every day | 395 | (8.0) |
Reported health status | ||
 Poor or fair | 202 | (4.1) |
 Good | 1287 | (26.1) |
 Very good | 1360 | (27.6) |
 Excellent | 2084 | (42.2) |
Household income (10000 Japanese yen/year) | ||
  < 200 | 488 | (9.9) |
 200 to < 400 | 859 | (17.4) |
 400 to < 600 | 1443 | (29.3) |
 600 to < 800 | 1092 | (22.1) |
 800 to < 1000 | 589 | (11.9) |
  ≥ 1000 | 462 | (9.4) |
Maternal educational level (years) | ||
  ≤ 12 | 1405 | (28.5) |
 13 to 15 | 1822 | (36.9) |
  ≥ 16 | 1706 | (34.6) |