When managing vitamin B12 deficiency, particularly alongside B12 injections, there are some important considerations:

1. Vitamin B12 Injections: These are an effective way to quickly boost your vitamin B12 levels, especially in cases of deficiency due to conditions like pernicious anemia where absorption from the gut is impaired¹².

2. Sublingual Methyl B12: Sublingual forms of vitamin B12, like methylcobalamin, can be beneficial as they are absorbed directly into the bloodstream, bypassing potential absorption issues in the digestive tract³. However, if you are already receiving injections as prescribed by your doctor, adding sublingual B12 might not provide significant additional benefits unless advised by a healthcare provider.

3. Vitamin B Complex: Taking a B-complex supplement can be beneficial if there are concerns about deficiencies in multiple B vitamins. It’s important to consult your healthcare provider to ensure you are using an appropriate dose, as these can help maintain overall energy metabolism and red blood cell production².

4. Folate (Methylfolate): You mentioned low folate levels, and methylfolate supplements can help boost these levels effectively while supporting red blood cell production³. It's essential to ensure that vitamin B12 levels are also addressed concurrently, as treating folate deficiency alone could mask symptoms of B12 deficiency³.

5. Iron and Vitamin D Deficiencies: Low ferritin and vitamin D levels also require attention. Iron supplements can help increase ferritin levels, improving oxygen transport in the blood, while vitamin D supplements can enhance calcium absorption and bone health².

It's important to coordinate all supplementation with your healthcare provider to tailor the treatment to your specific needs, monitor blood levels regularly, and avoid potential overstimulation or interactions between supplements²³.