Vitamin D deficiency.
With recent guideline changes to require that all infants be supplemented with vitamin D from birth, extreme presentations of vitamin D deficiency such as rickets are rare, but has vitamin D deficiency really gone away?
It is hard to pin down the prevalence of vitamin D deficiency in adolescents; it depends on the cut-off you use. In one study of 307 healthy Boston adolescents presenting for primary care, 24% were vitamin D deficient (serum 25[OH]D level, [less than or equal to] 15 ng/mL); of these 4.6% were severely vitamin D deficient (25[OH]D level, [less than or equal to]8 ng/mL) (Arch. Pediatr. Adolesc. Med. 2004;158:531-7). Broader studies have demonstrated the prevalence of vitamin D deficiency to be 7% for adolescent males aged 14-18 years and 10% for females that age (National Center for Health Statistics Data Brief No. 59, March 2011). This makes sense given that the natural sources of vitamin D are oily fishes such as salmon and sardines, cod liver oil, liver, egg yolk, and organ meat, none of which are big favorites in the adolescent population.
Other factors that contribute to the rise in D deficiency are the promotion of sunscreen use to block UV rays which are essential for cutaneous synthesis. Skin cancer prevention and the promotion of the use of sunscreen and a direct correlation of lower vitamin D levels have been identified (Am. J. Clin. Nutr. 2008;88:1519-27).
Obesity plays a unique role, in that it causes sequestration of the vitamin D into the fat cells. With the dramatic rise in adolescent obesity plus poor nutritional intake, vitamin D deficiency is the natural result.
Clinically it is easy for vitamin D deficiency to go unnoticed. Bones have mineralized, so the typical changes seen in the infant do not occur in the adolescent. But what is apparent is the generalized fatigue, muscle or bone pain, and increased upper respiratory infections. Adolescents with low vitamin D levels also are at increased risk for hypertension, elevated blood sugars, and metabolic syndrome.
Screening for vitamin D deficiency is imperative for the adolescent age group who have been identified to have risk factors because the deficiency can compound other illnesses, prevents appropriate bone mineralization, and decreases the patient's generalized sense of well-being. Serum 25(OH)D has a long half-life and is a better predictor of serum levels (Am. J. Clin. Nutr. 2008;88:582S-6S).
Supplementation of Vitamin D should be in the form of [D.sub.3], which has been shown to be more efficient in raising the serum level (Am. J. Clin. Nutr. 2012;95:1357-64), and dose will vary depending on the severity. Complimenting it with a calcium supplement also will improve bone mineralization and absorption.
Vitamin D deficiency is not a thing of the past. A simple nutritional review with every encounter allows for the educational opportunity for healthy eating and appropriate supplementation. The patient with recurrent upper respiratory infections should be encouraged to maintain a daily intake of at least 600 IU, but in patients with increased risk factors an actual blood test should be done to determine the amount that should be prescribed.
BY FRANCINE PEARCE, M.D.
Dr. Pearce is a pediatrician in Frankfort, III. She had no relevant financial disclosures. E-mail her at email@example.com. Scan this QR code or go to pediatricnews.com to view similar articles.
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|Date:||Jan 1, 2015|
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