Is vitamin D supplementation necessary for an 11-week-old infant with a suspected cow's milk protein allergy transitioning to an extensively hydrolyzed formula (eHF)?

Vitamin D Supplementation in Extensively Hydrolyzed Formula

Yes, vitamin D supplementation is necessary for this 11-week-old infant transitioning to extensively hydrolyzed formula (eHF), as infants with cow's milk protein allergy are at significantly increased risk for vitamin D deficiency, particularly those who are exclusively formula-fed or breastfed without adequate supplementation. 1, 2, 3

Why Vitamin D Supplementation is Critical

Infants with CMPA have documented vitamin D deficiency:

• Children with cow's milk protein allergy have significantly lower serum 25-hydroxyvitamin D levels compared to healthy controls (30.93 vs. 35.29 ng/mL; p=0.041), with a deficiency frequency of 20.3% versus 8.2% in controls 3
• CMPA is an independent risk factor for vitamin D deficiency by logistic regression analysis 2
• Vitamin D deficiency in CMPA infants is associated with persistent blood eosinophilia, delayed symptom resolution after cow milk elimination, and disturbed bone metabolism markers 2, 4

The mechanism of deficiency in CMPA:

• Elimination of cow's milk removes a major dietary source of calcium and vitamin D 1
• Even with appropriate commercial formulas, children with milk allergy are more likely to consume inadequate calcium and vitamin D compared to children without milk allergy 1
• At 11 weeks of age, this infant is at particularly high risk as younger infants with CMPA (mean age 1.6 months) have higher rates of vitamin D deficiency compared to older infants 4

Practical Supplementation Approach

Standard vitamin D supplementation should be provided:

• All infants require 400 IU/day of vitamin D supplementation per standard pediatric guidelines, regardless of feeding method 1
• This infant needs supplementation even while on eHF, as the formula alone may not provide adequate vitamin D given the increased risk profile 1, 3
• The American Academy of Pediatrics emphasizes that nutritional counseling reduces the possibility of consuming less-than-recommended intake of calcium and vitamin D in children with milk allergy 1

Monitoring Requirements

Regular nutritional surveillance is mandatory:

• All children with food allergy require nutritional counseling and regular growth monitoring 1
• Monitor serum 25-hydroxyvitamin D levels, particularly in this young infant who is at highest risk 2, 4, 3
• Track bone metabolism markers (bone-specific alkaline phosphatase, serum phosphorus, calcitonin) if growth concerns arise 2
• Children with 2 or more food allergies are at even higher risk for growth impairment 1

Critical Pitfalls to Avoid

Do not assume eHF alone provides adequate vitamin D:

• While eHF formulas are fortified, infants with CMPA have documented deficiency even with formula use 3
• The 71% of CMPA infants with serum 25(OH)D <75 nmol/L had persistent blood eosinophilia and delayed symptom resolution 4

Do not delay supplementation:

• Vitamin D insufficiency (25(OH)D <75 nmol/L) increases the odds of persistent symptoms by 3.7-fold (95% CI 1.1-12.6) 4
• Early supplementation at 11 weeks is crucial as younger infants show the highest deficiency rates 4

Ensure comprehensive nutritional counseling:

• Consultation with a registered dietitian is essential to ensure nutritional adequacy, with particular attention to calcium and vitamin D supplementation 1
• Regular growth monitoring (weight, length, head circumference) should be performed at each visit 1, 5