Malabsorption syndromes are seen in
intestinal tuberculosis, HIV, tropical sprue, parasites in stool
and Whipple’s Disease. Diabetes too can be the cause.
Since I cannot examine you and know other related conditions you may be having, nor is a detailed history possible on net, I have listed the various possibilities that should be looked into. Please consult your PCP to run tests and examination to clinch a diagnosis.