Vitamin D Deficiency & Primary Biliary Cirrhosis

Besides its synthesis in the skin by sunlight, vitamin D is chiefly absorbed in the gut from food sources such as fish, eggs, cod liver oil and vitamin D-fortified milk, all rich sources of vitamin D. Vitamin D is needed for the absorption of calcium in the gut. Vitamin D is inactive after its synthesis and also after absorption, it then has to be processed by the body before it is active. The liver and kidneys are involved in the processing of vitamin D. Primary biliary cirrhosis affects the liver, thereby affecting the activation of vitamin D.

Primary Biliary Cirrhosis

The liver is involved in the activation of vitamin D; it converts inactive vitamin D to hydroxy vitamin D. The liver also makes bile which flows through the bile ducts and down to the gallbladder where it is stored. Bile shakes up fat into smaller pieces, making it easy to be absorbed in the gut. Its action is analogous to that of a detergent when its used on oil or grease.

In primary biliary cirrhosis, the bile ducts become irritated, causing them to swell. Swelling of the bile ducts reduces and obstructs the flow of bile into the gallbladder and thereby leading to a backup of bile into the liver. Obstruction of the bile ducts is damaging to cells of the liver. Damage to the liver, inhibits the liver's role of processing vitamin D; this leads to low active vitamin D in the blood.

Complications

Primary biliary cirrhosis indirectly damages the liver by causing an obstruction of bile flow to the gallbladder. A damaged liver is inadequate in the processing of vitamin D which often leads to low blood calcium. Low blood calcium is a problem for the heart which requires adequate calcium in blood to function properly. Low blood calcium causes an irregular pulse. Very low blood calcium is a potential cause of irreversible heart failure, according to Wily Online Library.

There is typically an increased secretion of parathyroid hormone from the parathyroid gland because of low blood calcium. Excess parathyroid hormone release causes excessive bone breakdown and weakening of the bone.

Associated Symptoms

Shortness of breath while lying down occurs when the heart is weakened as a result of very low blood calcium. Leg and abdominal swelling also occur when calcium is very low.

Low blood calcium causes tetany, a condition of uncontrollable muscle contractions. It causes strange sensations over the lips and tongue as well as abnormal twitching of the facial muscles.

Low blood calcium by itself leads to weakening of the bone because calcium is needed to form healthy bone. Excessive parathyroid hormone released as a consequence of low blood calcium also contributes to the weakening of bone stimulating the breakdown of bone to release calcium to blood. This breakdown of bone results in bone and joint pain; other symptoms are generalized weakness, abdominal pain, nausea and sometimes depression.

Assessment

Evaluation of vitamin D deficiency begins with the sampling of blood from a vein of the arm. The blood sample is then taken to the lab and tested for levels of active vitamin D. A normal level of active vitamin D should be above 30 ng/mL; if less than 30 ng/mL, then it's abnormal. An active vitamin D level below 20 ng/mL is defined as vitamin D deficiency, according to Merck Manuals Online Medical Library.

Management.

Patients with primary biliary cirrhosis should get adequate treatment for their disease. While getting treatment, vitamin D should be supplemented as well to prevent loss of bone density. Vitamin D deficiency should be supplemented orally with 50 mcg of 25-hydroxyvitamin D3 daily or with intramuscular injections of vitamin D2 at a dose of 150,000 units once a week, for at least five months, according to the "International Journal of Gastroenterology and Hepatology."

Dietary modifications including the intake of fish, eggs, vitamin D-fortified milk and cod liver oil, should be considered since these foods are abundant sources of vitamin D.