Table 3.
Combination of descriptive and simple logistic regression analysis to show the relationship between risk factors and hypovitaminosis D (N = 396)
| Variable | Serum 25(OH)D <50 nmol/L n (%) mean ± SD median (IQR) | Serum 25(OH)D ≥50 nmol/L n (%) mean ± SD median (IQR) | Crude OR (95 % CI) | p value | ||
|---|---|---|---|---|---|---|
| Age(year)c | 27.91 ± 3.95 | 29.47 ± 5.07 | 0.91 | (0.84, 0.99) | 0.026 | |
| Ethnic groupsc | Malay | 296 (96.40) | 11 (3.60) | 22.42 | (9.63, 52.21) | <0.001 |
| Chinese | 24 (54.50) | 20 (45.5) | 1.00 | |||
| Indian | 32 (91.40) | 3 (8.60) | 8.89 | (2.36, 33.40) | 0.001 | |
| Others | 6 (60.00) | 4 (40.00) | 1.25 | (0.31, 5.06) | 0.754 | |
| Education levelc | Primary | 11 (68.80) | 5 (31.20) | 1.00 | ||
| Secondary | 136 (91.30) | 13 (8.70) | 4.75 | (1.43, 15.80) | 0.011 | |
| Tertiary | 211 (91.30) | 20 (8.70) | 4.80 | (1.52, 15.18) | 0.008 | |
| Working Status | Working | 275 (91.40) | 26 (8.60) | 1.00 | 0.252 | |
| Not working | 83 (87.40) | 12 (12.60) | 0.65 | (0.32, 1.35) | ||
| Household income per monthc | 3500 (2800,5000) | 3750 (2500,5250) | 1.00 | (1.00, 1.00) | 0.060 | |
| Household membersc | 3 (2,4) | 3 (2,5) | 0.90 | (0.75, 1.07) | 0.225 | |
| Weeks of pregnancy at first antenatal visitc | 10.0 (8.0,12.0) | 11.5 (8.0,12.0) | 0.89 | (0.77,1.02) | 0.100 | |
| Parityc | 0 (0,1) | 1 (0,1) | 0.79 | (0.61, 1.03) | 0.083 | |
| Last child birth | ≤ 2 years | 111 (89.50) | 13 (10.50) | 0.86 | (0.43,1.75) | 0.686 |
| >2 yearsa | 247 (90.80) | 25 (9.20) | 1.00 | |||
| Breastfeeding | Yes | 36 (87.80) | 5 (12.20) | 0.74 | (0.27,2.01) | 0.552 |
| Nob | 322 (90.70) | 33 (9.30) | 1.00 | |||
| BMI before pregnant (kg/m2) | 22.76 (20.00,26.25) | 22.15 (19.75,26.58) | 1.02 | (0.96,1.09) | 0.499 | |
| Weight at first antenatal visit (kg) | 57.85 (49.30,68.54) | 57.03 (51.49,65.61) | 1.01 | (0.98,1.03) | 0.569 | |
| Fitzpatrick Classificationc | Skin type I-II | 83 (80.60) | 20 (19.40) | 1.00 | ||
| Skin type III | 163 (94.20) | 10 (5.80) | 3.93 | (1.76,8.77) | 0.001 | |
| Skin type IV-VI | 112 (93.30) | 8 (6.70) | 3.37 | (1.42,8.03) | 0.006 | |
| Melanin Indices (using Mexameter) | (0-999.000) | 306.17 (254.17,373.67) | 242.83 (181.08, 354.00) | 1.01 | (1.00,1.01) | 0.006 |
| Sun protection score | (0-8)c | 5 (4,5) | 3.5 (1,5) | 1.77 | (1.42,2.21) | <0.001 |
| Total of respondents exposed to sunlight (10 am-2 pm) | Yes | 201 (90.10) | 22 (9.90) | 1.00 | ||
| No | 157 (90.80) | 16 (9.20) | 1.07 | (0.55,2.11) | 0.836 | |
| The length of time exposed to sunlight (minutes in week) | 35 (0,150) | 55 (0,210) | 1.00 | (1.00,1.00) | 0.570 | |
| Intake of vitamin D from food (IU/day)c | 197.51 (122.70,332.05) | 263.81 (142.90,460.55) | 1.00 | (1.00,1.00) | 0.042 | |
| Intake of vitamin D from food and supplements (IU/day) | 215.080 (132.93,361.98) | 302.135 (147.89,515.74) | 1.00 | (1.00,1.00) | 0.064 | |
| The level of vitamin D in foods and supplements (IU/day) | ||||||
| <200 IU/day | 165 (92.70) | 13 (7.30) | 1.64 | (0.82,3.32) | 0.165 | |
| ≥200 IU/day | 193 (88.50) | 25 (11.50) | 1.00 | |||
OR odds ratio, CI Confidence interval
p values have been derived from Wald tests
aRespondents with last child birth more than 2 years and respondents who did not have previous child (primid)
bRespondents who did not breastfeed during pregnancy and those who did not have children.
cIndependent variables included in the multiple logistic regression
1.00 as a reference group