u/Cool-Ask7444

I recently got bloodwork back showing:

• Vitamin D (25-hydroxy): 18 ng/mL
• B2 (riboflavin): <5.0 nmol/L

For context, I tested vitamin D deficient around 6 years ago but never consistently maintained my levels afterward. Since then I’ve had several health issues that may or may not be related.

My doctor prescribed:

• Vitamin D2: 50,000 IU once weekly
• 12 pills with 3 refills (potentially 48 weeks total)

I specifically asked if that duration was intentional because it seemed much longer than most protocols I’ve read about, and he confirmed it was. He also recommended adding daily D3 on top of the weekly D2.

After researching, I’ve seen a lot of people say:

• D3 is more effective than D2
• Some use a “loading phase” followed by maintenance dosing
• Magnesium and K2 may help support vitamin D utilization

Because of that, I’m trying to decide between:

1. Taking the prescribed weekly D2 + adding daily D3
2. Skipping the D2 entirely and using only D3 daily

I’m 5’10” and about 130 lbs if that matters for dosing.

Current thoughts from my research:

• Leaning toward magnesium glycinate
• Leaning toward K2 MK-7 over MK-4
• Seems common to take:
  • D3 + K2 earlier in the day with food
  • Magnesium at night

Questions:

• Would you personally take the prescribed weekly D2, or switch to D3-only?
• If using D3 daily, what dosing strategy makes sense for:
  • initial correction/loading
  • maintenance
• If combining weekly D2 with daily D3, what would a reasonable daily D3 dose look like?
• For magnesium:
  • what form do you recommend and why?
  • what dosage range tends to work well?
• For K2:
  • MK-4 vs MK-7?
  • what dosage range makes sense alongside vitamin D?
• Any timing recommendations that have worked well for you?

Regarding the B2 deficiency:
I haven’t researched this nearly as much yet, but I plan to ask my doctor about testing:

• magnesium
• zinc
• iodine

since I’ve read they may play roles in B2 activation/utilization.

Any insight is appreciated, thanks.