Determinants of serum 25-hydroxyvitamin D concentration in Finnish children: the Physical Activity and Nutrition in Children (PANIC) study

Abstract

We studied vitamin D intake, serum 25-hydroxyvitamin D (S-25(OH)D) concentration, determinants of S-25(OH)D and risk factors for S-25(OH)D <50 nmol/l in a population sample of Finnish children. We studied 184 girls and 190 boys aged 6-8 years, analysed S-25(OH)D by chemiluminescence immunoassay and assessed diet quality using 4-d food records and other lifestyle factors by questionnaires. We analysed the determinants of S-25(OH)D using linear regression and risk factors for S-25(OH)D <50 nmol/l using logistic regression. Mean dietary intake of vitamin D was 5·9 (SD 2·1) µg/d. Altogether, 40·8 % of children used no vitamin D supplements. Of all children, 82·4 % did not meet the recommended total vitamin D intake of 10 µg/d. Milk fortified with vitamin D was the main dietary source of vitamin D, providing 48·7 % of daily intake. S-25(OH)D was <50 nmol/l in 19·5 % of children. Consumption of milk products was the main determinant of S-25(OH)D in all children (standardised regression coefficient β = 0·262; P < 0·001), girls (β = 0·214; P = 0·009) and boys (β = 0·257; P = 0·003) in multivariable models. Vitamin D intake from supplements (β = 0·171; P = 0·035) and age (β = − 0·198; P = 0·015) were associated with S-25(OH)D in girls. Children who drank ≥450 g/d of milk, spent ≥2·2 h/d in physical activity, had ≥13·1 h/d of daylight time or were examined in autumn had reduced risk for S-25(OH)D <50 nmol/l. Insufficient vitamin D intake was common among Finnish children, one-fifth of whom had S-25(OH)D <50 nmol/l. More attention should be paid to the sufficient intake of vitamin D from food and supplements, especially among children who do not use fortified milk products.Key words: Vitamin D: 25-Hydroxyvitamin D: Children: Determinants Vitamin D is a pro-hormone that is converted in the liver to 25-hydroxyvitamin D (25(OH)D) and then in the kidney to 1,25-dihydroxyvitamin D, the active metabolite that regulates Ca, P and bone metabolism (1) . Vitamin D can be obtained from foods and supplements or synthesised endogenously in the skin in response to the UVB radiation of the sun. The major circulating form of vitamin D in serum is 25(OH)D, which is commonly used as an indicator of vitamin D status. Knowledge of the health effects of vitamin D is increasing. In addition to the well-known beneficial effect of vitamin D on bone health, there is some evidence that higher serum levels of 25(OH)D are associated with better muscle strength (2) and decreased risk of several diseases such as type 1 diabetes and other autoimmune diseases, cancer and infections (1) . The recommendations of the Institute of Medicine in the USA for serum 25(OH)D concentration and vitamin D intake are mainly based on the effects of vitamin D on bone health, because evidence on its effects on other outcomes is still not strong enough to inform the recommendations (3) . There is no consensus on the optimal serum level of 25(OH)D. The limit of serum 25(OH)D concentration for vitamin D deficiency varies between 25 and 50 nmol/l, and the lower limit ...

A History of Cow’s Milk Allergy Is Associated with Lower Vitamin D Status in Schoolchildren

“…In line with our findings, two recent Finnish studies showed increased 25(OH)D concentrations among 2- to 12-year-olds in 2003–2006 and 6- to 8-year-olds in 2007–2009 after the fortification of milk products with vitamin D began in 2003 [15, 16]. In their study, Mäkinen et al [15] reported that the frequency of vitamin D insufficiency in Finnish children almost halved from 69.9% in 1998–2002 to 37.3% in 2003–2006.…”

“…In our study, the majority of the children with milk allergy took vitamin D supplements, and the frequency of their fish consumption did not differ from that of the other children, but still their 25(OH)D levels were significantly lower. Our finding is similar to that of a recent study on 6- to 8-year-old Finnish children, where the strongest determinant of vitamin D status was consumption of milk, and it implies that vitamin D obtained from fortified dairy products is an effective means of improving the vitamin D status [16]. Those children who do not regularly consume fortified milk products are at risk of a lower vitamin D status and might benefit from higher vitamin D supplementation.…”

Vitamin D and Calcium Intakes, Physical Activity, and Calcaneus BMC among School-Going 13-Year Old Malaysian Adolescents

“…It was found that the mean value of vitamin D intake in this study was slightly higher compared to the EsKiMo study, where the intake was 2.55 µg/day in males and 2.50 µg/day in females, but was lower compared to an earlier study on Finnish girls [57], where their intake was 4.3 µg/day. A recent study found that the mean vitamin D intake from both food and supplements for Finnish children was 5.9 µg/day in males and 7.7 µg/day in females [58]. Even though female adolescents have higher BMC value compared to male adolescents, it has been found that the male adolescents have a normal mean BMC level but with a tendency for higher vitamin D intake and higher physical activity levels ( p = 0.001) compared to females.…”

Definition of Vitamin D Deficiency in Schoolchildren: Systematic Review With Meta-Analysis

“…One study performed seasonal supplementation of 13,700 IU over seven days (TABLE 1). None of the studies reported side effects during supplementation (19)(20)(21)(22)(23)(24) . (24) 159 Canadian children of both sexes.…”

“…The reviewed articles differ in some respects such as the serum 25(OH)D values considered to be deficient, insufficient or adequate. Three of the six articles considered deficiency as levels below 20 ng/ mL (19)(20)(21) , one considered it as below 18 ng/mL (22) , another below 15 ng/mL (23) , and the latter below 11 ng/mL (24) . Therefore, half of the studies analyzed considered deficiency as below 20 ng/mL.…”