Researchers propose new vitamin D cutoffs for infants

Most infants are born with vitamin D deficiency; however, for many, the condition spontaneously improves within the first 9 months of life, according to study findings presented at the annual Pediatric Academic Societies Meting in Baltimore.

“The high prevalence of vitamin D deficiency reported from different researchers worldwide may not be the true reflection of the status of vitamin D deficiency,” Uday Mandal, MD, of the department of pediatrics at LLRM Medical College in Meerut, Uttar Pradesh, India, and colleagues wrote. The researchers sought to determine the incidence of vitamin D deficiency among infants and to identify the level of vitamin D sufficient to trigger the physiologic parathyroid hormone axis, “so as to differentiate truly deficient from sufficient vitamin D status.”

In a prospective cohort study, Mandal and colleagues analyzed data from 96 infants enrolled at birth and followed for 9 months. Researchers estimated serum 25-hydroxyvitamin D levels in cord blood and again at 14 weeks; 77 infants were followed at 9 months for growth and estimation of serum 25-(OH)D levels, parathyroid hormone (PTH), alkaline phosphatase (ALP), calcium and phosphorus. Vitamin D deficiency was defined as a serum 25-(OH)D level less than 15 ng/mL.

All infants were vitamin D deficient at birth. Mean serum 25-(OH)D levels rose from 8.94 ng/mL at birth to 14.04 ng/mL at 3 months and 15.78 ng/mL at 9 months. Researchers found that 17% of infants became vitamin D sufficient without supplementation by age 3 months; 25% became vitamin D sufficient by age 9 months.

Researchers found an inverse association between serum 25-(OH)D and serum PTH (P < .001), and serum ALP (P < .001), and a positive correlation between serum 25-(OH)D and serum calcium (P < .001).

A surge in serum PTH was observed only in infants with a vitamin D level less than 10.25 ng/mL.

“Vitamin D deficiency [is] common in infancy, but incidence decreases spontaneously even without supplementation,” the researchers wrote. “A large number of babies may be falsely labeled as vitamin D deficient with currently followed cutoffs. A new cutoff for vitamin D deficiency needs to be established for infants.” – by Regina Schaffer

Reference:

Mandal U, et al. Poster #139. Presented at: Pediatric Academic Societies Meeting; April 30-May 3, 2016; Baltimore.

Disclosure: Endocrine Today was unable to determine relevant financial disclosures.