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Ask Dr. H: The importance of Vitamin D

Question: My doctor drew my Vitamin D level and is recommending that I take 50,000 units of Vitamin D once a week. That sounds like a lot. I'm 58. How important is Vitamin D?


My doctor drew my Vitamin D level and is recommending that I take 50,000 units of Vitamin D once a week. That sounds like a lot. I'm 58. How important is Vitamin D?

-F.M., Wilkes-Barre, Pa.


Vitamin D, the "sunshine vitamin," is far more important to our health than most folks realize. It's the hottest vitamin under study these days, with new studies coming out every month showing how supplemental Vitamin D can protect against osteoporosis, heart disease, ovarian cancer, colon cancer, kidney cancer, prostate cancer, Parkinson's disease, multiple sclerosis, dementia, fatigue, psoriasis, tuberculosis and colds/flu. Did you ever consider that colds and flu are worst in the winter, when sunlight and Vitamin D levels are at their lowest?

We know that the prevalence of folks with low levels of Vitamin D is about 50 percent. A normal Vitamin D level (measured as a 25-hydroxy Vitamin D level) is between 30 and 100, with a target of at least 50-60 for optimal disease prevention. A toxic level of Vitamin D is greater than 200, and it's really difficult to exceed that limit with daily or weekly Vitamin D supplementation.

The U.S. RDA recommends a conservative dose of 400-600 units of Vitamin D per day, failing to consider that individual Vitamin D levels may still show deficiency. I've had several patients, including a pilot and a software engineer, with undetectable Vitamin D levels!

Milk contains only 100 units of Vitamin D per eight-ounce glass. If you live north of the latitude line of Atlanta, no amount of sunshine in the winter can raise your Vitamin D level. A rough rule of thumb is that every 100 units of Vitamin D taken daily will raise your Vitamin D blood level by one. With supplementation, I recommend monitoring the Vitamin D and calcium levels every three months.


My father died from a condition called "polyarteritis nodosa." I've never quite understood what it is, other than it caused him to suffer a heart attack. Can you explain it?

-C.T., Atlanta


"Polyarteritis nodosa" (PAN) is a rare form of vasculitis, an inflammation of the muscular walls of arteries. It's serious, because the blood flow supplied by those arteries is greatly reduced. In this form, small and medium-size blood vessels can develop weaknesses in their walls leading to aneurysms and sudden blood vessel rupture.

Why this blood vessel inflammation occurs is unknown. For some reason, the person's immune system begins attacking its own blood vessel walls as if they were a foreign invader. We call this an "autoimmune reaction" - the same sort of inappropriate attack that causes rheumatoid arthritis.

PAN is not hereditary. Viruses (especially hepatitis B) or bacterial infection may trigger it by inducing a hypersentivity reaction.

Making the diagnosis of PAN can be tough. There isn't any blood test. Symptoms are often vague, particularly since vasculitis can involve arteries in many areas of the body. The most common cause of death is from kidney damage that leads to severe high blood pressure and kidney shutdown. A ruptured aneurysm may also cause death.

The only way to diagnose PAN for certain is by performing a biopsy of the involved tissue when vasculitis is suspected.

Treatment of PAN is often difficult because so many blood vessels and organs are affected. Steroids are the first line. When that fails, more powerful immune-suppressing drugs like methotrexate and Cytoxan are used. Without treatment, almost all who have PAN die within 2-5 years. With early diagnosis and treatment, 10-year survival can be as high as 90 percent.