A liver enzyme called glutathione, or GSH, is a major source of vitamin D, the key vitamin that prevents the buildup of vitamin A, a potent sun protection factor that can lead to skin cancer and other conditions.

The key to maintaining good health is to maintain good GSH levels.

But what if you have liver disease, or if you don’t have the proper GSH level?

And what if your GSH has been declining?

“When you have the right type of GSH you can maintain your vitamin D levels,” said Dr. Michael H. Stegemann, M.D., associate professor of medicine at Boston Children’s Hospital and an expert on vitamin D. “But if you’re not getting the right kind of Gsh, you’re going to lose a lot of your vitamin A.”

GSH is a hormone that regulates a person’s body’s natural production of vitamin B12, a vitamin essential to maintaining health.

People with liver disease or other liver disorders that can cause liver failure are most at risk of vitamin C deficiency, a deficiency in the enzyme responsible for the absorption of vitamin K. “It’s one of the worst things you can do to your vitamin system,” Dr. Stecemann said.

“If you’re having a lot more vitamin C deficiencies, you’ll have a lot less vitamin D production.

And that could be damaging.”

How do I get a GSH reading?

If you have signs of liver disease such as: fatigue or nausea, changes in your urine or stool, red or dark spots in your skin, changes to your skin tone or the appearance of dark patches on your face or hands, your liver enzyme level should be checked to be sure it’s stable.

You should get your liver enzymes tested by a doctor who has expertise in vitamin D and liver health.

You can also get a liver enzyme test kit online or at a pharmacy.

If your test results show that your liver levels are normal, you should talk to your doctor about a treatment plan.

Your doctor can help you choose which vitamin D supplements you should take.

They’ll also tell you which liver enzyme supplements are safe for you.

Some supplements, such as those made from flaxseed, can cause side effects.

Other supplements, like those made with soy or rice, can be beneficial.

But you can still get enough vitamin D from other foods and supplements to maintain optimal health.