Table 1. Summary of prevalence of vitamin D deficiency and its determinants from National population based studies in Southeast Asia.
| China8 Nutrition and Health of Aging Population in China (NHAPC) project |
South Korea9 Korean Fourth Korea National Health and Nutrition Examination Surveys (KNHANESIV)* |
Thailand10 Thai 4th National Health Examination Survey (2008–9) cohort (NHESIV)** |
|
|---|---|---|---|
| Date of subjects enrollment | April to June 2005 |
2008 | 2008–2009 |
| Latitude of residency | Beijing (40° N) and Shanghai (31° N) | 33° N and 38° N | 5°30′ N and 20°30′ N |
| No. of subjects | 3,262 | 6,925 | 2,641 |
| Mean age (year) | 50–70 | M: 42 ± 20 (10–91) F: 45 ± 19 (10–93) |
Total: 40 ± 0 M: 40 ± 1 F: 41 ± 0 |
| M/F | 1,443/1819 (44/56%) | 3,047/3,878 (44/56%) | 1,321/1,320 (50/50%) |
| BMI (kg/m2) | - Reported BMI according to 25(OH)D quintile -The mean of BMI = 24–25 |
Classified BMI in to 3 groups: < 23: 45% in M 53% in F 23–25: 24% in M 20% in F ≥ 25: 31% in M 27% in F |
Total: 24 ± 0 M: 23 ± 0 F: 24 ± 0 |
| Method of 25(OH)D measurement | RIA (Diasorin, Stillwater, MN) |
RIA (Diasorin, Stillwater, MN) |
LC-MS/MS |
| Mean 25(OH)D (nmol/L) | 40.4 | M: 53 ± 19 F: 46 ± 18 |
Total: 79 ± 1 M: 86 ± 1 F: 73 ± 1 |
| Percent of subjects with 25(OH)D < 50 nmol/L | Total: 69% | M: 47% F: 65% |
Total: 6% M: 2% F: 9% |
| Percent of subjects with 25(OH)D < 75 nmol/L | 94% | M: 87% F: 94% |
Total: 45% M: 33% F: 57% |
| Latitude at risk | Northern (Beijing) | N/A | Southern part (excluding Bangkok: a capital city of Thailand) |
| Season with the lowest 25(OH)D levels | N/A | spring, winter | N/A |
| Predictors for vitamin D deficiency | - living in northern (Beijing) and urban area - having a physical examination in April - having higher educational levels - having a family history of CVD and diabetes - having less physically active - being female |
Analyzed in adult 20–80 y (both gender): - younger age (20–49 y) - living in urban - occupations (indoors worker) - no regular exercise |
- being female - younger age - living in urban area - living in Bangkok |
Data from National population based study in Asia. *Data was expressed as mean ± standard deviation (mean ± SD). **Data was expressed as mean ± standard error of mean (mean ± SEM). M, male; F, female; BMI, body mass index; RIA, radioimmunoassay; LC-MS/MS, liquid chromatography/tandem mass spectrometry; CVD, cardiovascular disease.