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HIV and Vitamin D Deficiency

How Does Vitamin D Deficiency Impact HIV?

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Updated September 07, 2009

Though it isn't unique to people infected with the virus, studies suggest that HIV and vitamin D deficiency often go hand-in-hand. This is worrisome because vitamin D is an important nutrient for bone health, calcium balance and immune function.

People living with HIV and vitamin D deficiency may experience bone disorders, low CD4 counts and increased AIDS progression, so doctors are taking a closer look at vitamin D levels in all of their HIV patients.

Where Do We Get Our Vitamin D?

Vitamin D is one of the body's fat soluble vitamins. Unlike may other vitamins, it is only found in a few food sources (fish; fortified foods, such as milk and cereals). Most of it is manufactured by the body itself.

How does the body manufacture vitamin D? Through sun exposure. Actually, a whopping 90% of our vitamin D comes from sunlight. Specifically, ultraviolet rays from sunlight cause the skin to produce vitamin D. There is a cholesterol-like molecule in the skin that is modified by exposure to the sun's ultraviolet rays. This molecule is released into the circulatory system and makes its way to the liver. Once in the liver, it is converted to 25-hydroxyvitamin D, the precursor to the vitamin D used throughout the body.

Vitamin D can also be found in vitamin supplements. It can be taken in pill form, either as a single vitamin or as part of a multivitamin tablet. There are also prescription medicinal sources of vitamin D that are given to patients with such illnesses as kidney disease. One specific prescription drug is called calcitrol, a steroid hormone and source of vitamin D that helps the body regulate calcium levels in the blood.

Why Do People Become Vitamin D Deficient?

Typically, people are deficient in vitamin D for one of three reasons.

Certain diseases can cause vitamin D deficiency, the most common of which is renal disease. In fact, people with kidney failure or kidney disease typically need to take vitamin D supplements or prescription medications to maintain normal vitamin D levels.

In addition, because there are few food sources of vitamin D, diet cannot be relied on to prevent vitamin D deficiency.

The last one is a bit of a double-edge sword. When experts recognized the dangers of the sun, sun-blocking preparations were developed to block the harmful effects of the rays, and the importance of sun safety precautions got increased attention. A benefit to protecting people from skin cancer? Yes. But these important precautions also blocked the beneficial effects of the sun -- namely, vitamin D production. Without enough exposure to sunlight and UV rays, the body cannot manufacture enough vitamin D, increasing the risk for deficiency.

Why Are HIV-Positive People Particularly at Risk for Vitamin D Deficiency?

In addition to the above three reasons, researchers have found that HIV-infected people seem more prone to vitamin D deficiency for a few reasons.

People living with HIV use more vitamin D for normal bodily processes than others do.

In addition, they have defects in renal hydroxylation. This is a process that adds a hydrogen and oxygen molecule to 25-hydroxyvitamin D in order to convert it to a form of vitamin D the body can use. When that system is defective, there is less vitamin D available to the body.

There is even some data that relates vitamin D deficiency to the use of HIV medications from the class non-nucleoside reverse transcriptase inhibitors (NNRTIs). Examples of these drugs include Sustiva and Viramune.

How Is Vitamin D Deficiency Diagnosed?

A simple blood test: By measuring the amount of 25-hydroxyvitamin D in the blood, your doctor can determine if you have enough vitamin D.

How Vitamin D Deficiency Is Treated

Luckily, there is a relatively easy way to restore your vitamin D supplies -- taking vitamin D supplements. Your doctor can prescribe you a dose that is appropriate for you; a common dose prescribed is 50,000 IU of vitamin D2 or D3 taken orally once each week for 8 weeks. After restoring your vitamin D level, your doctor will typically prescribe a dose of 400 to 800 IU of vitamin D3 taken orally per day. Some experts suggest that upward of 1000 IU of vitamin D is required each day to maintain a healthy balance.

At your next visit to your HIV specialist, talk to him or her about vitamin D and your vitamin D level. Make certain that deficiency is not a problem for you and that you are doing everything you can to maintain a healthy level of this important vitamin.

Sources:

Cannell, J.; "Diagnosis and Treatment of Vitamin D deficiency"; Expert Opinion on Pharmacology; Jan. 2008, Vol 9, No. 1, Pgs 107-118.

Evans, D.; "High Prevalence of Vitamin D Deficiency in HIV-Positive Men"; POZ Magazine; 29 July 2009.

Raloff, J.; "Vitamin D and HIV"; Science Magazine; 16 Oct 2004; Vol 166, No.16.

Villamor, E.; "A Potential Role for Vitamin D on HIV Infection?"; Nutrition Reviews; 15 July 2008; Vol 64, No. 5, Pgs 226-233.

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