Vitamin D inadequacy is widespread in Tunisian active boys and is related to diet but not to adiposity or insulin resistance

Figures & data

Fig. 1 Plasma 25-hydroxyvitamin D concentrations in Tunisian active children according to body mass (n=225).

Fig. 2 Correlations of plasma 25-hydroxyvitamin D with daily intake of red meat, fish, eggs, and milk in Tunisian active children (n=174).

Fig. 3 Daily intake of proteins, red meat, fish, eggs, and milk according to the vitamin D status in Tunisian active children (n=174).

Table 1 Clinical, nutritional, and biochemical characteristics of children according to body mass (n=225)

	Normal-weight children (n=105)	Overweight children (n=48)	Obese children (n=72)	P
Age, years	11.4±2.81	11.1±2.08	11.5±2.04	0.203
Peak height velocity, years	−3.51 (1.90)	−2.80 (2.30)	−2.00 (2.30)	<0.001
Fat mass,%	17.5 (6.71)	28.3 (3.72)	35.3 (3.73)	<0.001
Total energy intake^a, cal/day	2550±624	2652±800	2843±809	0.006
Vitamin D intake^a, µg/day	8.21±3.60	8.53±4.45	8.20±4.55	0.224
Parathyroid hormone, µg/L	39.3±22.0	37.4±15.4	37.5±27.3	0.832
Calcium, mg/L	95.1±4.14	95.8±3.72	96.2±3.84	0.147
Phosphorus, mg/L	42.5±3.91	42.8±5.04	43.6±4.42	0.702
Glucose, mg/dL	89.9±6.77	89.6±7.77	91.3±7.01	0.337
Insulin, UI/L	5.35 (3.58)	8.55 (6.05)	11.7 (9.14)	<0.001
HOMA-IR	1.14 (0.79)	1.31 (1.44)	2.65 (2.10)	<0.001
QUICKI	0.375±0.035	0.358±0.029	0.335±0.034	<0.001
C-reactive protein, mg/L	0.41 (0.60)	0.62 (2.71)	0.91 (2.32)	<0.001

Values are expressed as mean±SD or median (inter quartile range); HOMA-IR, homeostasis model assessment of insulin resistance; QUICKI, quantitative insulin sensitivity check index.

^aCollected in 174 children.

Table 2 Plasma 25-hydroxyvitamin D and multi-adjusted odd-ratios for vitamin D deficiency/insufficiency in children according to confounding variables

			Plasma 25-OHD, µg/L	Vitamin D deficiency^a		Vitamin D insufficiency^b
		N	Mean (SD)	%	OR (IC à 95%)^c	%	OR (IC à 95%)^c
Maturity status	Pre-PHV Around/post-PHV	194 31	14.1±5.25 13.5±4.07	40.7 41.2	– 1.89 (0.54–6.67)	83.0 97.1	– 6.76 (0.89–51.2)
Body mass	Normal-weight Overweight/obesity	105 120	13.8±4.79 14.3±5.38	40.0 41.7	– 1.34 (0.50–3.64)	89.5 80.8	– 3.09 (0.81–11.8)
Adiposity	No Yes	86 139	13.7±4.52 14.4±5.39	39.3 41.0	– 0.81 (0.29–2.24)	91.7 80.6	– 4.41 (0.97–18.1)
Insulin resistance	No Yes	111 114	14.2±5.25 13.9±4.97	39.8 41.6	– 1.07 (0.47–2.45)	83.2 86.7	– 1.82 (0.60–5.66)
Skin color	Fair Dark	59 166	15.9±5.19 13.3±4.88***	25.8 46.4	– 1.40 (0.60–3.25)	77.4 88.0	– 1.89 (0.66–5.44)
Vitamin D intake	≥8.34 µg/day <8.34 µg/day	85 89	15.3±5.29 14.7±4.90	31.8 36.0	– 2.63 (1.06–6.51)*	81.2 82.0	– 1.45 (0.50–4.22)
Milk intake	≥500 ml/day <500 ml/day	87 87	12.8±4.25 17.1±4.97***	19.5 48.3	– 3.32 (1.32–7.90)**	69.0 94.3	– 5.83 (1.75–19.4)**
Red meat intake	≥100 g/week <100 g/week	86 88	13.3±4.76 16.7±4.87***	22.1 45.5	– 3.42 (1.46–8.01)**	73.3 89.8	– 3.63 (1.23–10.7)*
Fish intake	≥100 g/week <100 g/week	84 90	12.7±4.53 17.4±4.51***	13.1 53.3	– 6.23 (2.64–14.7)***	70.2 92.2	– 5.93 (1.87–18.7)**
Egg intake	≥50 g/day <50 g/day	73 101	13.3±4.37 17.2±5.12***	17.8 45.5	– 2.94 (1.25–6.92)*	68.5 91.1	– 3.74 (1.27–11.0)*

PHV, pick of high velocity; OR, odd-ratio; 95% CI, 95% confidence interval; 25-OHD, 25-hydroxyvitamin D; ^a25-OH D<12 µg/L; ^b25-OHD<20 µg/L; ^cadjusted for maturation status, BMI, skin color, fat mass, HOMA-IR, and intake of vitamin D, milk, red meat, fish, and eggs; *p<0.05; **p<0.01; ***p<0.001.