Your
Vitamin B12 level is significantly low (<148 pg/mL), and your
Vitamin D level is also low (16.6 ng/mL). Injectable vitamin B12 replacement is reasonable, and the prescribed regimen may be appropriate depending on the exact formulation and dosage.
However, before starting Arachitol 6L weekly for 4 weeks, please confirm the exact strength and formulation with your treating doctor. High-dose vitamin D is commonly used for deficiency, but the cumulative dose alone does not establish safety.
Calcium and renal function should also be considered, and vitamin D levels can be reassessed after treatment.
Your haemoglobin is normal, which does not exclude vitamin B12 deficiency. If you have tingling, numbness, difficulty walking or other neurological symptoms, ensure prompt treatment and follow-up.
Your ALT (57 U/L) and ALP (159 U/L) are mildly elevated and warrant further evaluation, including GGT, bilirubin and repeat
liver function tests as appropriate.
My advice: Do not change the prescribed regimen independently. Confirm the exact vitamin D dose before the next injection and arrange follow-up to assess treatment response and the cause of both deficiencies.