A vitamin pill may pass through your intestines and out in stool. You may need other vitamin shots as well because of a shortened small intestine. A dietitian can assess this and I would suggest you make an appointment. A healthy balanced diet that contains adequate protein and calories appropriate for an individual's height and weight is recommended for persons with lupus. If you start taking steroids to reduce inflammation, then you may need to limit salt and follow a diabetic diet.
Steroids increase blood pressure and blood sugar.
Also, steroids, depending on the dose, can cause skin to become thinner and bruise more easily. There is a web site for lupus by Hamline University in St Paul, Minnesota. They have a talk group for persons with lupus and a platform for researchers to share information on new treatments available. The site also has lots of information regarding diagnosis and current treatment.