I needed supplementation in this area as well and continue to supplement. I also was tested when I ate an ample amount of meat so don't let that fool you... don't assume that if you eat meat, eggs etc you will have plenty of B12. It all comes down to the health of your intestines/digestion because you also need to know that everything you eat may not be assimilated into your body and used appropriately in your body if your intestines are not working properly. Correct any deficiencies but also find out and correct intestinal/digestion issues as well. A holistic doctor can help you with this. If you have Lupus you probably have food allergies/intolerances...don't just believe me check the Books To Read on Healing at the very beginning of this blog. Here is the link.
Books to Read on Healing http://lupushope.blogspot.com/2009/03/books-to-read-on-healing.html
B12 Deficiency Symptoms http://sites.google.com/site/jccglutenfree/b12deficiencysymptoms