Taking "the promising results of vitamin D administration in experimental autoimmune animal models into account, it's intriguing to speculate that vitamin D may also have potential beneficial effects in autoimmune liver disease in man".Several forms of vitamin D exist. The two major forms are vitamin D2 or ergocalciferol, and vitamin D3 or cholecalciferol, vitamin D without a subscript refers to either D2 or D3 or both. These are known collectively as calciferol.
"Prof. Ran Tur-Kaspa, from the Rabin Medical Center- Beilinson Campus in Israel and his team worked on hepatitis C, the major factor in chronic liver disease that can lead to cirrhosis. It is also the main cause in the Western world of organ failure requiring a liver transplant and is one of the causes of primary liver cancer"."He and his team investigated ordinary vitamin D, which is already taken by many people as prevention for numerous diseases, to see whether it had any effect on hepatitis C and on liver cells that host it. They discovered and published in Hepatology, a peer-reviewed medical journal, that vitamin D directly halts the activity of viruses in general and hepatitis C in particular. They also found that a system for actively producing vitamin D is found in liver cells and can activate the immune system and repress the virus".
What is the prevalence of vitamin D deficiency, according to your most recent study findings?
Vitamin D deficiency is extremely common in our patient population. We conducted a study of 118 patients with liver disease, and a total of 109 (92.4%) patients had some degree of vitamin D deficiency. This finding is also reflected in other reports. The deficiency was seen even in patients without liver failure, though the severity of deficiency—expressed as very low levels of vitamin D (<7 ng/mL)—was more common in patients with cirrhosis (29.5% vs 14.1%; P=.05).
What health benefits are connected to vitamin D?
A 2007 report in The New England Journal of Medicine noted several health benefits associated with vitamin D. More recently, vitamin D has been shown to play an important role in reducing the risk of many chronic diseases, including type 2 diabetes mellitus, cardiovascular diseases, cancers, and autoimmune and infectious diseases. These effects may be secondary to both local production of calcitriol and its autocrine and paracrine actions on cellular proliferation and differentiation, apoptosis, insulin and renin secretion, interleukin, and bactericidal proteins production.
What health risks are posed by vitamin D deficiency?
Vitamin D is a key player in calcium absorption, and deficiency can lead to decreased calcium absorption, which can, in turn, cause bone diseases such as rickets or osteomalacia. These diseases are associated with prolonged and severe vitamin deficiency and are not seen in the western world. However, subclinical vitamin D deficiency (or vitamin D insufficiency) is extremely common and may contribute to the development of osteoporosis by decreasing absorption of calcium.
Vitamin D deficiency also causes muscle weakness, and adequate levels are required for optimal function and strength of the muscle. Studies have found low vitamin D levels to be associated with frequent falls.
The best ways to prevent vitamin D deficiency are sun exposure, fortified food, and fish oil .
Should patients with liver disease be monitored for vitamin D deficiency?
Yes. All hepatologists should monitor vitamin D levels and treat deficient patients. The goal for all patients with chronic liver disease should be a 25-OH vitamin D level of 30 ng/mL. Anything less than 15–20 ng/mL is considered deficiency.
Has vitamin D deficiency always been a problem for people with liver disease, or has this been changing recently?
It is likely that it was always a problem, but the data from the National Health and Nutrition Examination Survey indicate that the mean serum level of 25-OH vitamin D has decreased over the last 2 decades. It may be that the more severe vitamin D deficiency is only now coming to light.