Vitamin D deficiency is very common in patients with fatty liver disease as evidenced by our observations in the Metabolic Liver Clinic and that reported by others. We also observed that patients with more severe fatty liver disease had lower Vitamin D concentrations. Others have shown that replacing Vitamin D in patients with cirrhosis is effective and even patients with Vitamin D replete status have lowering of Vitamin D over time if not supplemented.

One of the measures of liver injury in NAFLD is the plasma concentration of ALT and we will use this to follow patients as is currently done as standard of care. All patients in the Metabolic Liver Clinic are being routinely screened for Vitamin D deficiency as standard of care and treatment is being started with oral supplementation, but there are not standardized protocols to determine success of therapy. We hypothesize that patients with NAFLD with low Vitamin D levels will respond appropriately to Vitamin D supplementation for 6 months.

Inclusion Criteria:

• Adults of age 18 or greater
• Diagnosis of fatty liver disease with a low Vitamin D level (< 30 ng/dl) in the past 6 months
• Able to give consent

Exclusion Criteria:

• Those currently receiving Vitamin D supplementation

The study population for this study is patients who have fatty liver disease. Patients who have low vitamin D (<30ng/dL) and patients who have normal vitamin D (> or = to 30ng/dL) will be followed for six months and observed.

No plan to share data, needs HIPPA clearance and specific IRB approval, we did not plan on original data being shared