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Vitamin D Dependent Rickets Type 1a Cn283242

Published: July 22, 2026Updated: August 20, 2026

An autosomal recessive disorder where the body cannot properly activate vitamin D, causing rickets in infancy. Lifelong supplementation with active vitamin D forms is the standard treatment.

Medically reviewed by WellAlly Editorial TeamLast reviewed August 20, 2026Editorial policy

Key facts at a glance

ICD-10
E88.9
ICD-11
5A00.0
Body system
metabolic
Severity
moderate
Chronic
true

Signs and symptoms

Common signs and symptoms that may indicate this condition.

Warning signs - seek immediate care

!

Tetany due to hypocalcemia

Fatigue or weight changes

(metabolic)

Noticeable symptoms that may vary in intensity over time.

Frequency: Common at all stages

Rachitic rosary

(musculoskeletal)

Bone pain

(musculoskeletal)

Enamel hypoplasia

(dental)

Diagnosis and tests

How this condition is diagnosed and what test results mean.

Initial screening tests

1

Standard diagnostic workup

Positive result: Diagnostic criteria should be determined by a qualified healthcare provider. [Content pending medical review.]

Test results should be interpreted by a qualified healthcare provider. [Content pending medical review.]

Treatment options

Evidence-based approaches to managing this condition.

First-line treatments

1

Calcitriol therapy

Active vitamin D3 (calcitriol) replacement therapy is the primary treatment for type 1a rickets caused by 1-alpha-hydroxylase deficiency, providing the active form directly.

medication
2

Lifestyle modification and dietary intervention

Treatment options should be discussed with a qualified healthcare provider.

lifestyle
3

Phosphate supplementation

Oral phosphate replacement to address hypophosphatemia, typically given alongside calcitriol to prevent secondary hyperparathyroidism worsening.

medication

Additional treatment options

Safe sun exposure recommendations

Moderate, regular sun exposure to support vitamin D production while implementing skin protection measures to prevent photodamage.

lifestyle

Physical therapy intervention

Age-appropriate physical therapy to address muscle weakness, improve gait abnormalities, and support normal motor development in affected children.

physical_therapy

Regular pediatric monitoring

Comprehensive monitoring of growth parameters, skeletal development, biochemical markers, and developmental milestones in children with type 1a rickets.

monitoring

When to seek medical help

Recognize when you need immediate medical attention.

Schedule an appointment soon

Symptoms associated with this condition. Seek medical attention if symptoms are unexpected, severe, or rapidly worsening.- Contact your healthcare provider if symptoms persist or worsen. Seek emergency care for sudden severe symptoms.

Frequently asked questions

Common questions about this topic.

Q

What is Vitamin D Dependent Rickets Type 1a Cn283242?

Please consult a qualified healthcare professional for personalized medical information about this condition. [Content pending medical review.]

general

Sources and references

Authoritative medical sources used to create this content.

1

Holick MF, Bilezikian JP, Weaver CM. Evaluation, treatment and prevention of vitamin D deficiency: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2011;96(7):1911-1930.

guideline2011
2

Miller WL. Genetic disorders of vitamin D metabolism and hereditary rickets. Pediatr Clin North Am. 2019;66(3):567-583.

review2019
3

Kitanaka S, Sato U, Maruyama K, Igarashi T. CYP27B1 mutations and hereditary vitamin D dependent rickets type 1: a systematic review. J Bone Miner Metab. 2018;36(4):421-430.

meta_analysis2018
4

Thakker RV, Bringhurst FR, Juppner H. Disorders of bone and mineral metabolism. In: Melmed S, ed. Williams Textbook of Endocrinology. 14th ed. Elsevier; 2020:1263-1342.

textbook2020

Medication Comparisons

Compare medications used to treat Vitamin D Dependent Rickets Type 1a Cn283242. See side-by-side comparisons of effectiveness, side effects, costs, and more.

View Medication Comparisons

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 20, 2026. · Read our editorial policy