Vitamin D and Genetics in Nutritional Rickets

Mayo Clinic

Status and phase: Completed; Phase 4

Conditions: Nutritional Rickets

Treatments: Dietary Supplement: Vitamin D3; Dietary Supplement: Vitamin D2; Dietary Supplement: Calcium; Dietary Supplement: Vitamin D + Calcium

Study type: Interventional

Funder types: Other

Identifiers

NCT00949832

07-006041

Details and patient eligibility

About

The purpose of this study is:

1. To compare the response of rickets to calcium with and without vitamin D.
2. To assess whether vitamin D increases calcium absorption in calcium deficiency rickets.
3. To compare the response of children with and without rickets to orally administered vitamin D3 and vitamin D2
4. To identify mutations that influence calcium and vitamin D metabolism among families of children with rickets in Nigeria and Bangladesh.
5. To assess the functional status of the 25-hydroxylase enzyme in families possessing a 25-hydroxylase mutation.

Full description

Previous studies of Nigerian children with rickets demonstrated the superiority of calcium over vitamin D in producing healing. It is not known whether the addition of vitamin D to calcium will produce a better response to treatment than calcium alone in Nigerian children. A previous study suggested the possibility that vitamin D may augment the effect of calcium. We will compare the response of rickets to calcium with and without vitamin D. In addition, very little human data clearly demonstrates the effect of supplemental vitamin D on calcium absorption. We will assess whether oral vitamin D increases the already high calcium absorption even further.

Recent published data indicate that the increase in serum 25-hydroxyvitamin D may be more sustained with vitamin D3 than with vitamin D2. We will compare the response of Nigerian children with and without rickets to orally administered vitamin D3 and vitamin D2.

Because nutritional rickets tends to run in families, we will also examine amplified DNA for evidence of mutations that influence calcium and vitamin D metabolism among families of children with rickets in Nigeria and Bangladesh. Families possessing a recently identified 25-hydroxylase mutation will be given oral vitamin D2 and vitamin D3 to determine the functional status of the 25-hydroxylase enzyme.

Enrollment: 109 patients

Sex: All

Ages: 6 months to 16 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Clinical features of rickets
• Active rickets on X-ray

Exclusion criteria

• Treatment with calcium or vitamin D in preceding 30 days

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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109 participants in 4 patient groups, including a placebo group

Vitamin D + Calcium

Active Comparator group

Description:

Vitamin D and calcium supplementation

Treatment:

Dietary Supplement: Vitamin D + Calcium

Calcium

Placebo Comparator group

Description:

Calcium supplementation

Treatment:

Dietary Supplement: Calcium

Vitamin D2

Active Comparator group

Description:

Vitamin D2 response

Treatment:

Dietary Supplement: Vitamin D2

Vitamin D3

Active Comparator group

Description:

Vitamin D3 response

Treatment:

Dietary Supplement: Vitamin D3