hi ,I`m 47 years , male ,,feeling tirdness ,, easly exhausted 1) my Bp , pulse , Respiratory rate : normal 2) B suger , Renal functions ( urea , creatinine ) normal 3) BMI 40 4) sgpt ,, cpk ,, alkaline phosphatase ,, normal 5) SGOT 110 ,, 6) suffering from avascular necrosis hips bilateral ,, & familiar 7) vitamin d is always low despite of oral vit d treatment for 5 months 7) should I perform liver biopsy ,, or what metabolic error could i have