Vitamin D
Vitamin D explained
Vitamin D measures vitamin D status (25‑OH vitamin D) to evaluate deficiency, sufficiency, and monitor supplementation.
Varies by laboratory (LDT/CLIA; not FDA‑approved as a drug)Vitamin D helps treat
• Vitamin D deficiency/sufficiency
• Bone health and calcium metabolism
• Monitoring supplementation
additional medications
• Related clinical evaluation and history
• Repeat testing to confirm abnormal results
• Additional targeted labs as recommended
medication risks
• False positives/negatives leading to unnecessary anxiety or missed diagnoses
• Privacy and insurance implications depending on results
• Pre‑analytical variables (fasting, meds) can affect accuracy
side effects
• Bruising or soreness at draw site
• Lightheadedness or fainting (rare)
• Infection at puncture site (very rare)
FAQs
Q: Target levels?A: Targets vary; follow clinician and guideline ranges.
Q: Sunlight/supplements effect?
A: Yes—both impact levels.
Q: How often to test?
A: Per clinician, often 8–12 weeks after dose changes.
Q: Fasting?
A: Not usually required.
Q: Insurance?
A: Commonly covered when medically necessary.
