Table 4. Prevalence Rate Ratios for plasma vitamin C deficiency (<11 µmol/L) compared to adequate (>28 µmol/L).
Univariable analysis | Multivariable analysis | |||||
PRR1 | 95% CI | p | PRR2 | 95% CI | p | |
Age Group | ||||||
60–64 | 1 | 1 | ||||
65–69 | 1.05 | 0.99, 1.10 | 1.07 | 1.02, 1.12 | ||
70–74 | 1.11 | 1.05, 1.17 | 1.08 | 1.03, 1.14 | ||
75–79 | 1.11 | 1.04, 1.19 | 1.09 | 1.02, 1.16 | ||
80+ | 1.17 | 1.09, 1.25 | 1.14 | 1.07, 1.22 | ||
P trend | <0.0001 | <0.0001 | ||||
Women | 0.91 | 0.86, 0.96 | <0.0001 | 0.93 | 0.89, 0.98 | 0.003 |
Lowest SES3 | 1.11 | 1.04,1 .18 | <0.0001 | 1.03 | 0.99, 1.07 | 0.2 |
Biomass fuels | 1.25 | 1.14, 1.20 | <0.0001 | 1.03 | 0.98, 1.09 | 0.02 |
Malnutrition | 1.13 | 1.07, 1.20 | <0.0001 | |||
Body mass Index | ||||||
<18.5 | 1.11 | 1.06,1 .16 | <0.0001 | 1.05 | 1.03, 1.09 | <0.001 |
≥18.5–<25 | 1 | 1 | ||||
≥25 | 0.91 | 0.84, 0.96 | 0.002 | 0.97 | 0.93, 1.02 | 0.3 |
Diabetes | 1.02 | 0.97,1.07 | 0.6 | 1.01 | 0.97, 1.05 | 0.6 |
Current tobacco 4 | ||||||
North India | 1.09 | 1.02, 1.15 | 0.01 | 1.07 | 1.01, 1.13 | 0.02 |
South India | 1.34 | 1.19, 1.50 | <0.0001 | 1.29 | 1.18, 1.41 | <0.0001 |
Dietary vitamin C5 | ||||||
<18 | 1 | 1 | ||||
>18–29 | 0.88 | 0.83, 0.93 | 0.99 | 0.95, 1.03 | ||
>29–44 | 0.80 | 0.76, 0.86 | 0.95 | 0.91, 0.99 | ||
>44 | 0.73 | 0.68, 0.77 | 0.90 | 0.86, 0.94 | ||
P trend | <0.0001 | <0.0001 | ||||
Season 6 | ||||||
North India | ||||||
December to February | 1 | 1 | ||||
March to May | 1.11 | 0.96, 1.29 | 0.2 | 1.09 | 0.95, 1.25 | 0.2 |
June to September | 1.33 | 1.21, 1.46 | <0.0001 | 1.27 | 1.16, 1.38 | <0.0001 |
October to November | 1.27 | 1.16, 1.40 | <0.0001 | 1.27 | 1.17, 1.38 | <0.0001 |
South India | ||||||
December to February | 1 | |||||
March to May | 0.86 | 0.61, 0.91 | 0.03 | 0.83 | 0.74,0.94 | 0.003 |
June to September | 0.74 | 0.61, 0.91 | 0.004 | 0.73 | 0.61,0.89 | 0.001 |
October to November | 0.87 | 0.77, 0.99 | 0.04 | 0.91 | 0.78,1.06 | 0.2 |
Prevalence rate ratios adjusted for age and sex.
Prevalence rate ratios adjusted for variables in the Table.
Socio-Economic status.
interaction for tobacco use and vitamin C deficiency by location, p = 0.001.
Quartiles of dietary vitamin C (mg/day).
interaction for season and vitamin C deficiency by location, p <0.0001.