Does your lab report give the ranges for that lab with the results?

This can be important, because of lab procedures and calibration.

If you are in US 444 for B12 is just barely normal. The lowest normal now is considered to be 400pg/ml.

Your MMA level seems odd.
From the net:
The reference range of MMA is 0-0.4 µmol/L (0-4.7 µg/dL).
from http://emedicine.medscape.com/article/2108967-overview

Elevated MMA indicates that B12 is not working in the body, so the MMA builds up. One wants to see a very low number for MMA, therefore.

This link gives arsenic ranges:
http://www.atsdr.cdc.gov/toxguides/toxguide-2.pdf

So your arsenic level needs explanation.

Your magnesium is in the low end of normal.
http://www.nlm.nih.gov/medlineplus/e...cle/003487.htm
This is common in the US where 70% of Americans show
some low magnesium levels.
So eating more foods that contain it, and avoiding diuretics like alcohol and caffeine, and diuretic drugs, may help that.
You can take a supplement like SlowMag twice a day. Or soak in epsom salt baths.

Your folate is elevated:
http://www.everydayhealth.com/health...d-results.aspx
This is common when there are B12 problems.

You may not be methylating B12 and folic acid properly.

So you can start taking methylcobalamin and methylfolate OTC and see if that helps. Most doctors will not suggest anything with your test result. they are not aware of the new guidelines.

Folic acid is in fortified foods now in the US. If you cannot methylate (activate to folate) either, then it will build up in the serum. This failure is a genetic error and pretty common. Left untreated it can lead to cardiovascular damage and disease.

There is a DNA test for MTHFR genetic polymorphism if you care to delve more deeply into it.

Do the magnesium because it is really helpful for most people.
Here is my magnesium thread.
http://neurotalk.psychcentral.com/thread1138.html

Methylcobalamin: 5mg daily orally on an empty stomach. Do for 3 months, and evaluate results. Your levels should be over 1000.

Methylfolate: Metafolin by Solgar, 800mcg a day to start.

Both of these are available online, example:
iherb.com