What is the recommended treatment for vitamin D deficiency in a 14-year-old?

Vitamin D Treatment for a 14-Year-Old

For a 14-year-old with vitamin D deficiency, prescribe 50,000 IU of vitamin D3 (cholecalciferol) once weekly for 8-12 weeks, followed by daily maintenance of 1,500-2,000 IU. 1

Initial Loading Phase

• Administer 50,000 IU of vitamin D3 once weekly for 8-12 weeks to rapidly restore vitamin D levels to the target range of at least 30 ng/mL 1, 2
• Vitamin D3 (cholecalciferol) is strongly preferred over vitamin D2 (ergocalciferol) because it maintains blood levels longer and has superior bioavailability in adolescents 1, 2
• This loading dose approach is necessary because standard daily doses would take many weeks to normalize severely low levels 2

Maintenance Phase After Loading

• Transition to 1,500-2,000 IU daily after completing the 8-12 week loading phase to maintain optimal vitamin D levels 1
• An alternative maintenance regimen is 50,000 IU once monthly, which may be easier for some families to remember and equals approximately 1,600 IU daily 1
• Daily dosing is physiologically more natural than intermittent dosing for pediatric patients 2

Essential Co-Interventions for Bone Health

• Ensure adequate calcium intake of 1,000-1,300 mg daily from diet and supplements, as calcium is necessary for vitamin D therapy to work properly 1, 2
• Good dietary calcium sources include milk, yogurt, cheese, fortified plant milks, and leafy greens 1
• If calcium supplements are needed, take them in divided doses of no more than 600 mg at once for optimal absorption 2
• Encourage weight-bearing exercise (running, jumping, sports) for at least 30 minutes, 3 days per week to build strong bones 1

Monitoring Protocol

• Measure 25(OH)D levels after 3 months of treatment to ensure adequate response and confirm levels have reached at least 30 ng/mL 1, 2
• The target 25(OH)D level is at least 30 ng/mL (75 nmol/L) for optimal bone health and fracture prevention 1, 2
• If levels remain below 30 ng/mL after 3 months, increase the maintenance dose 1
• Individual response to vitamin D supplementation varies due to genetic differences in metabolism, making monitoring essential 2
• Continue monitoring periodically (every 6-12 months) while on maintenance therapy 2

Safety Considerations

• Daily doses up to 4,000 IU are considered completely safe for adolescents, and the prescribed treatment is well below levels that could cause harm 1, 2
• The upper safety limit for blood levels is 100 ng/mL, far above the target range 1, 2
• Vitamin D toxicity is extremely rare and only occurs with prolonged intake of very high doses (typically over 10,000 IU daily for extended periods) 1
• Avoid single ultra-high loading doses (>300,000 IU) as they may be inefficient or potentially harmful 2
• Vitamin D toxicity symptoms include hypercalcemia, hyperphosphatemia, and hypercalciuria, though toxicity is rare at recommended doses 2

Special Considerations

• If malabsorption is suspected (celiac disease, inflammatory bowel disease, cystic fibrosis), higher doses may be required and specialist consultation is warranted 2
• Vitamin D administration from fortified foods, dietary supplements, and prescription sources should be evaluated to prevent excessive total intake 3
• Pediatric doses must be individualized, and progress should be followed with frequent monitoring when using therapeutic doses 3