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Table 1 Characteristics of study participants

From: Prevalence and predictors of vitamin D deficiency in young African children

  Overall Kenya Uganda Burkina Faso The Gambia South Africa
No. of participants (%) 4509 (100%) 1361 (30.1%) 1301 (28.9%) 329 (7.3%) 629 (13.9%) 889 (19.7%)
Median 25(OH)D nmol/L (IQR)a 77.6 (63.6, 94.2) 81.0 (66.3, 101.6) 78.6 (65.1, 94.5) 78.4 (64.5, 91.3) 71.2 (59.1, 84.2) 76.2 (60.6, 91.9)
Vitamin D status
 25(OH)D > 150 nmol/l 79/4509 (1.8%) 51/1361 (3.7%) 17/1301 (0.1%) 4/329 (1.3%) 1/629 (0.2%) 6/889 (0.7%)
 25(OH)D > 75 nmol/l 2485/4509 (55.1%) 815/1361 (59.9%) 756/1301 (58.1%) 186/329 (56.5%) 265/629 (42.1%) 463/889 (52.1%)
 25(OH)D 50–75 nmol/l 1674/4509 (37.1%) 464/1361 (34.1%) 479/1301 (36.8%) 123/329 (37.4%) 302/629 (48.0%) 306/889 (34.4%)
 25(OH)D < 50 nmol/l 350/4509 (7.8%) 82/1361 (6.0%) 66/1301 (5.1%) 20/329 (6.1%) 62/629 (9.9%) 120/889 (13.5%)
 25(OH)D < 30 nmol/l 28/4509 (0.6%) 4/1361 (0.3%) 5/1301 (0.4%) 0/329 (0%) 2/629 (0.3%) 17/889 (1.9%)
Median age (months) 23.9 (12.3, 35.9) 19.8 (12.7, 36.8) 24.1 (23.9, 35.9) 23.4 (19.7, 26.4) 46.6 (35.2, 58.7) 12.0 (11.9, 12.1)
Age categories (months)
 < 12 816/4509 (18.1%) 300/1361 (22.0%) 24/1301 (1.8%) 19/329 (5.8%) - 473/889 (53.2%)
 12–24 1597/4509 (35.4%) 555/1361 (40.8%) 440/1301 (33.8%) 172/329 (52.3%) 15/629 (2.4%) 415/889 (46.7%)
 24–36 1029/450 (22.8%) 153/1361 (11.2%) 587/1301 (45.1%) 138/329 (42.0%) 150/629 (23.9%) 1/889 (0.1%)
 36–48 478/4509 (10.6%) 146/1361 (10.7%) 167/1301 (11.8%) - 165/629 (26.2%) -
 48+ 589/4509 (13.1%) 207/1361 (15.2%) 83/1301 (6.4%) - 299/629 (47.5%) -
Sex: females 2216/4509 (49.1%) 671/1361 (49.3%) 641/1301 (49.3%) 161/329 (48.9%) 297/629 (47.2%) 446/889 (50.2%)
Seasoneb
 Summer/short rains/dry 867/4503 (19.3%) 285/1361 (20.9%) 331/1296 (25.5%) 72/329 (21.9%) - 179/889 (18.1%)
 Autumn/dry 1475/4503 (32.8%) 896/1361 (65.8%) 295/1296 (22.8%) 123/329 (37.4%) - 161/889 (18.1%)
 Winter/long rains 1361/4503 (30.2%) 86/1361 (6.3%) 330/1296 (25.5%) 129/329 (39.2%) 536/628 (85.4%) 280/889 (31.5%)
 Spring/dry 800/4503 (17.8%) 94/1361 (6.9%) 340/1296 (26.2%) 5/329 (1.5%) 92/628 (14.7%) 269/889 (30.3%)
Nutritional statusc
 Stunted 581/2289 (25.4%) 99/208 (47.6%) 203/1282 (15.8%) 103/307 (33.5%) 176/492 (35.8%) n/a
 Underweight 389/2487 (15.6%) 102/389 (26.2%) 103/1296 (8.0%) 58/309 (18.8%) 126/493 (25.6%) n/a
 Wasted 147/2285 (6.4%) 24/205 (11.7%) 59/1281 (4.6%) 20/307 (6.5%) 44/492 (8.9%) n/a
Inflammationd 1019/4469 (22.8%) 363/1344 (27.0%) 306/1285 (23.8%) 109/322 (33.9%) 85/629 (13.5%) 156/889 (17.6%)
Malariae 445/3293 (13.5%) 227/1082 (20.8%) 89/1280 (7.0%) 64/303 (21.1%) 65/628 (10.4%) n/a
  1. South African children were not exposed to malaria
  2. IQR inter-quartile range, n/a not available, 25(OH)D 25-hydroxyvitamin D
  3. aMedians (interquartile ranges) are presented. bSeasons were based on 3 monthly intervals: 1st season, December to February; 2nd season, March to May; 3rd season, June to August; 4th season, September to November. In South Africa, the seasons correspond to summer, autumn, winter and spring, respectively, in Uganda and Kenya there are two rainy and two dry seasons and in Burkina Faso and The Gambia there is a single rainy and dry season. However, timing of the rains is often unpredictable and may vary from these times. cStunted was defined as height-for-age Z score < − 2; underweight as weight-for-age Z score < − 2, wasted as weight-for-height Z score < − 2 (denominator number varied because anthropometry data was not available for South African children). dInflammation as CRP > 5 mg/L or ACT > 0.6 g/L. ACT, but not CRP, was available for The Gambia. eMalaria as the presence of P. falciparum parasites on blood film