Please assess the completion status of the following clinical trial:

Trial Title: Vitamin D Supplementation for Adults With Neurofibromatosis Type 1 (NF1)

Study Design Characteristics:
- Allocation: RANDOMIZED
- Intervention Model: SINGLE_GROUP
- Observational Model: None
- Primary Purpose: PREVENTION
- Time Perspective: None
- Masking: DOUBLE
- Phase: PHASE2
- Number of Arms: 2.0

Eligibility Criteria:
Inclusion Criteria:~All individuals with NF1 (neurofibromatosis type 1), based on NIH diagnostic criteria, who are between the ages of 25 and 40 years, may participate in this study. All participants will be enrolled in the study and then screened for serum 25(OH)D levels, and all individuals with levels between 9 and 29ng/ml (inclusive) are eligible for vitamin D supplementation -~Exclusion Criteria:~1. diagnosis of Paget's disease, hyperthyroidism, hyperparathyroidism, or other medical condition that affects bone health~2. they foresee that they will be unable to comply with the two-year study protocol~3. Pregnant, planning to conceive within the next two years, or is less than 6 months post-delivery or lactation.~4. vitamin D supplementation in the last 3 months equal to or greater than 600IU per day~5. oral or IV glucocorticoid use for over 3 months~6. bisphosphonate therapy for more than 3 months~7. calcitonin therapy for more than 3 months~8. calcium supplementation in last 3 months equal to or greater than 1000mg per day~9. malignant peripheral nerve sheath tumor (MPNST)~10. history of kidney stones in last 5 years~11. individuals with metal instrumentation in spine or hip that preclude accurate DXA interpretation.~12. inability to obtain blood samples on routine venipuncture~13. anti-epileptic medical therapy~14. anticoagulant medical therapy

- Gender: ALL
- Minimum Age: 25 Years
- Maximum Age: 40 Years
- Healthy Volunteers: f

Study Arms:
- cholecalciferol 600 IU (Type: ACTIVE_COMPARATOR): cholecalciferol in Ddrops form at either 600 International units per day versus 4,000 IU per day
- cholecalciferol 4,000 IU (Type: ACTIVE_COMPARATOR): Cholecalciferol at 4,000 IU per day in the form of liquid Ddrops

Based on this trial design, predict the completion outcome and termination type (if applicable).