Table 2.

Demographic characteristics, season of sampling and laboratory variables according to vitamin D status among 1218 children aged from 6 months to 14 years, south-west China, 2011

	Deficiency (25(OH)D < 10 ng/ml)		Insufficiency (25(OH)D = 10–29 ng/ml)		Sufficiency (25(OH)D >30 ng/ml)
Variable	n or Mean	% or sd	n or Mean	% or sd	n or Mean	% or sd	P value
Total	263	21·6	334	27·4	621	51·0
Gender							0·246§
Male	160	22·2	199	27·6	362	50·2
Female	103	20·7	135	27·2	259	52·1
Age group							<0·001§
< 1 year	9	4·2	30	18·9	177	81·9
1–3 years	73	12·3	164	22·7	355	60·0
4–7 years	110	40·6	98	36·2	63	23·2
8–14 years	71	51·1	42	30·2	26	18·7
Season of blood samples*							0·351§
Spring	62	26·8	59	25·5	110	47·6
Summer	91	18·8	149	30·8	244	50·4
Autumn	61	18·5	83	25·2	186	56·4
Winter	49	28·3	43	24·9	81	46·8
Hb category†							0·354§
Anaemic	25	24·3	26	25·2	52	50·4
Non-anaemic	238	21·3	308	27·6	569	51·0
Pb level (μg/dl)							<0·001§
>10	12	54·5	6	27·3	4	18·2
5–10	180	26·0	205	29·6	308	44·4
<5	71	14·1	123	24·4	309	61·4
Pb level (μg/dl)‡	6·49	2·57	5·61	1·61	5·27	1·52	<0·001||
Hb level (g/dl)‡	12·32	0·91	12·37	0·95	12·38	0·99	0·745||

25(OH)D, 25-hydroxyvitamin D.

*Spring = March to May; summer = June to August; autumn = September to November; winter = December to February.

†Anaemia was defined as Hb < 11·0 g/dl for ages 0·5–4·99 years, < 11·5 g/dl for ages 5–11·99 years and <12·0 g/dl for ages 12–14 years.

‡Data are presented as mean and standard deviation.

§The χ ² test was performed to test the differences between variables; P < 0·05 was considered statistically significant.

||ANOVA was performed to test the differences between variables; P < 0·05 was considered statistically significant.