Guidelines for Vitamin D Intake

From Medscape Medical News
American Academy of Pediatrics Updates Guidelines for Vitamin D Intake CME/CE
Laurie Barclay, MD & Désirée Lie, MD, MSEd

10/14/2008
Pediatrics. Published online October 13, 2008. 2008;122:1142-1152.

Clinical Context

Rickets and vitamin D deficiency are preventable conditions with adequate nutritional intake of vitamin D but are still prevalent in the United States and other Western countries, particularly in exclusively breast-fed infants and in those with chronic diseases. Rickets has a peak incidence of ages 3 to 18 months and may present with hypocalcemic seizures.

This is an update of the 2003 AAP guidelines for vitamin D intake in children and adolescents, which recommended a daily intake of 200 IU of vitamin D daily beginning at 2 months of life, to account for evidence showing that a higher intake is necessary to avoid vitamin D deficiency and insufficiency.

Study Highlights

There is evidence that 400 IU of vitamin D daily not only prevents rickets but also treats the condition.
In adults, vitamin D deficiency is defined as a level of 25-hydroxyvitamin D less than 50 nmol/L and vitamin D insufficiency as a level of 50 to 80 nmol/L.
The main source of vitamin D is via skin synthesis from cholesterol after exposure to UVB light.

Those most susceptible to vitamin D insufficiency include breast-fed infants, those with low sunlight exposure, those with dark skin pigmentation that takes 5 to 10 times longer to generate vitamin D3, and those with chronic diseases such as cystic fibrosis and fat malabsorption.
Mothers who are vitamin D deficient may expose their fetuses and infants to higher risk for vitamin D deficiency after birth and during lactation, and their vitamin D status should be monitored.
Inadequate vitamin D status in pregnant women has an effect on fetal skeletal development, tooth enamel formation, and general fetal growth.
However, universal recommendations for high-dose vitamin D supplementation during pregnancy are not available at present, and recommendations for supplementation in children are thus necessary.

Vitamin D levels in breast milk vary from less than 25 IU/L to 78 IU/L, and infants who are exclusively breast-fed are at increased risk for deficiency.

Vitamin D supplementation should begin at birth or in the first few days of life with 400 IU per day for breast-fed and partially breast-fed infants.
Supplementation should be continued unless the infant is weaned to 1 L per day or 1 quart per day of vitamin D–fortified formula or whole milk.

Whole milk should not be used until after age 12 months, and reduced-fat milk is recommended for those with obesity.
All non–breast-fed infants and older children ingesting less than 1 L per day of vitamin D–fortified milk or formula should receive 400 IU of vitamin D daily.
Adolescents are at increased risk for vitamin D deficiency because the intake of milk was reduced by 36% between the 1970s and the 1990s.
Adolescents should be encouraged to drink milk daily (100 IU per 8-oz serving) and to consume vitamin D–fortified foods (cereals and eggs).
1 L of vitamin D–fortified milk daily is required to meet the daily vitamin D recommendations for adolescents.
Without adequate dietary intake, adolescents should be supplemented with 400 IU of vitamin D daily.
According to available evidence, serum levels of 25-hydroxyvitamin D in infants and adolescents should be 50 nmol/L or higher.
In children with additional risk factors for vitamin D deficiency, such as those with chronic diseases, those receiving seizure medications, or those with fat malabsorption, higher doses of vitamin D may be needed daily.
In these children, levels of 25-hydroxyvitamin D should be monitored every 3 months until normal levels have been achieved with vitamin D supplementation.
Pediatricians and other healthcare professionals should make vitamin D supplements readily available to children in their community, especially those at risk for deficiency or insufficiency.

Pearls for Practice

Vitamin D supplementation at 400 IU per day should begin within the first few days of life and is especially recommended in breast-fed children, and supplementation may be higher for children with additional risk factors.
Adolescents who do not consume adequate vitamin D in their diet should have an intake of 400 IU of vitamin D supplements daily.