In the JournalsPerspective

Several risk factors associated with vitamin D deficiency in children

Vitamin D deficiency was common among children in the United Kingdom, and although there were common risk factors for lower 25-hydroxyvitamin D3 and 25-hydroxyvitamin D2 levels, there were also distinct risk factors for each, according to researchers from the University of Bristol, England.

Data were taken from the Avon Longitudinal Study of Parents and Children, a population-based birth cohort from southwest England. Of the 14,062 live births included in the cohort — established between April 1991 and December 1992 — 7,560 of the children had data on serum 25-(OH)D3 and 25-(OH)D2 concentrations. These nonfasting blood samples were collected at a mean age of 9.9 years.

The median levels were 22.3 mg/mL for 25-(OH)D3, 1.4 ng/mL for 25-(OH)D2 and 24.3 ng/mL for total 25-(OH)D. In all, 2,158 children were vitamin D deficient, with total 25-(OH)D levels of less than 20 ng/mL, and 5,631 children were vitamin D insufficient, with 25-(OH)D levels of less than 30 ng/mL.

Vitamin D deficiency was more common during the winter months. Winter season, higher age, female gender, nonwhite ethnicity, lower household income, rental housing, time spent outdoors during summer and higher Tanner stage were associated with vitamin D deficiency.

Lower 25-(OH)D3 and D2 levels were associated with age, gender, puberty stage, BMI, physical activity, household income and maternal education. Ethnicity, vitamin D intake, time spent outdoors and UVB protection score were associated with 25-(OH)D3 only. Protein and carbohydrate intake, parents’ social class and housing tenure were associated with 25-(OH)D2 only.

“Sources for these two forms are different, and our study showed that despite some overlap, there are differences in potential confounding structures for association studies of 25-hydroxyvitamin D3 and 25-hydroxyvitamin D2,” the researchers wrote. “Future studies should consider these differences when assessing associations of vitamin D status with health outcomes.”

PERSPECTIVE

Mark A. Sperling, MD
Mark A. Sperling

This study doesn’t say that much new that we don’t know. There are two ways we can get vitamin D: Sunshine is the main source of vitamin D3, and green leafy vegetables are the main source of vitamin D2. Nonwhite children had less D3, which is understandable because they have a natural sun block. Children who spent time outdoors had higher D3 levels, which is also understandable. Boys had increased D3 levels and D2 levels, which is understandable because boys spend more time outdoors. Also of interest, obese children had lower D3 levels and D2 levels because they don’t often spend time outdoors nor do they eat the healthy vegetables.

Mark A. Sperling, MD
Endocrine Today Editorial Board member

Disclosure: Dr. Sperling reports no relevant financial disclosures.

Twitter Follow EndocrineToday.com on Twitter.

Vitamin D deficiency was common among children in the United Kingdom, and although there were common risk factors for lower 25-hydroxyvitamin D3 and 25-hydroxyvitamin D2 levels, there were also distinct risk factors for each, according to researchers from the University of Bristol, England.

Data were taken from the Avon Longitudinal Study of Parents and Children, a population-based birth cohort from southwest England. Of the 14,062 live births included in the cohort — established between April 1991 and December 1992 — 7,560 of the children had data on serum 25-(OH)D3 and 25-(OH)D2 concentrations. These nonfasting blood samples were collected at a mean age of 9.9 years.

The median levels were 22.3 mg/mL for 25-(OH)D3, 1.4 ng/mL for 25-(OH)D2 and 24.3 ng/mL for total 25-(OH)D. In all, 2,158 children were vitamin D deficient, with total 25-(OH)D levels of less than 20 ng/mL, and 5,631 children were vitamin D insufficient, with 25-(OH)D levels of less than 30 ng/mL.

Vitamin D deficiency was more common during the winter months. Winter season, higher age, female gender, nonwhite ethnicity, lower household income, rental housing, time spent outdoors during summer and higher Tanner stage were associated with vitamin D deficiency.

Lower 25-(OH)D3 and D2 levels were associated with age, gender, puberty stage, BMI, physical activity, household income and maternal education. Ethnicity, vitamin D intake, time spent outdoors and UVB protection score were associated with 25-(OH)D3 only. Protein and carbohydrate intake, parents’ social class and housing tenure were associated with 25-(OH)D2 only.

“Sources for these two forms are different, and our study showed that despite some overlap, there are differences in potential confounding structures for association studies of 25-hydroxyvitamin D3 and 25-hydroxyvitamin D2,” the researchers wrote. “Future studies should consider these differences when assessing associations of vitamin D status with health outcomes.”

PERSPECTIVE

Mark A. Sperling, MD
Mark A. Sperling

This study doesn’t say that much new that we don’t know. There are two ways we can get vitamin D: Sunshine is the main source of vitamin D3, and green leafy vegetables are the main source of vitamin D2. Nonwhite children had less D3, which is understandable because they have a natural sun block. Children who spent time outdoors had higher D3 levels, which is also understandable. Boys had increased D3 levels and D2 levels, which is understandable because boys spend more time outdoors. Also of interest, obese children had lower D3 levels and D2 levels because they don’t often spend time outdoors nor do they eat the healthy vegetables.

Mark A. Sperling, MD
Endocrine Today Editorial Board member

Disclosure: Dr. Sperling reports no relevant financial disclosures.

Twitter Follow EndocrineToday.com on Twitter.