Vitamin D / B12 Supplementation

Supplementation begins with a conversation about your symptoms, diet, and health history, followed by a blood draw to measure your vitamin D and B12 levels. We interpret those results alongside the rest of your bloodwork to confirm a true deficiency rather than guessing.

Based on your numbers, we recommend a specific form, dose, and schedule, whether that is an oral supplement or, for certain B12 deficiencies, an injection. We then recheck your levels over time to confirm the plan is working and adjust as needed.

No special preparation is needed for vitamin D or B12 testing, and you do not usually need to fast unless we are drawing other labs at the same time, such as a lipid panel or glucose work.

Bring a list of any vitamins, over-the-counter products, and prescriptions you currently take so we can review them together during your medication review. This helps us avoid duplicate dosing and tailor your plan safely.

Most people take their supplement consistently and return for a follow-up blood test, typically after a few months, so we can confirm your levels have normalized. Vitamin D in particular is monitored to keep it in a healthy range rather than pushed higher than needed.

If low B12 or vitamin D is connected to another issue, such as anemia or bone health concerns, we coordinate your care accordingly and involve a Cedars-Sinai specialist when that is the right next step.