Vitamin D & Liver Function

Vitamin D is not considered an essential vitamin for liver function, but liver function is essential to providing vitamin D to the body. The liver and kidneys change vitamin D to an active form, which actually is hormonal in nature. Because of this, people with liver disorders can develop vitamin D deficiencies.

Food Sources

• Foods with vitamin D are few, mainly fatty fish liver, beef liver and eggs. It can be difficult to obtain enough this way, so some foods are fortified, including milk, cereal and bread. Vitamin D is also readily obtained from sun exposure, but still must be converted by the liver and kidneys for use.

Vitamin D Conversion

• Conversion of vitamin D to its active form is called hydroxylation. The first hydroxylation occurs in the liver and the second in the kidneys.

Fat Malabsorption

• People who have fat malabsorption, or difficulty absorbing dietary fat, may need vitamin D supplementation because it is fat soluble. Liver impairment can cause fat malabsorption.

Chronic Liver Disease

• University of Tennessee researchers measured vitamin D levels of patients with chronic liver disease, such as hepatitis and cirrhosis, and found over 92 percent had some level of vitamin D deficiency.

Cirrhosis

• Severe vitamin D deficiency in the Tennessee study was more likely in people with cirrhosis than with other liver issues.