Research Finds Vitamin D May Be Crucial in Preventing Cardiovascular Disease and Fighting Infections

A growing body of evidence is finding that adequate levels of Vitamin D are important not only in maintaining healthy bones but also in reducing risk for cancer, heart disease, stroke, diabetes, autoimmune diseases, and infections.  Unlike other essential vitamins, Vitamin D is a hormone your body can make when skin is exposed to the sun. Vitamin D is not present in most foods but is found in fortified milk and fatty fish.  However these sources do not provide adequate Vitamin D for many people, especially for persons who are older, obese, have darker skin, or live in colder climates like New York.   An estimated 40%-75% of people in the U.S. are deficient in Vitamin D. 

Here are some highlights of recent studies revealing the importance of Vitamin D to heart health.   It is believed Vitamin D reduces blood vessel inflammation and therefore is an important ingredient in the prevention of heart disease.  A recent review of 75 research studies on Vitamin D and heart disease concluded there is evidence low Vitamin D levels are associated with unhealthy blood pressure & blood sugar levels, and the development of coronary artery disease.  Several recent studies add to these conclusions. One study found that post-menopausal women with low Vitamin D levels have more risk factors for heart disease than those with adequate Vitamin D levels.  Another recent study found that people who took 4,000 IU of Vitamin D daily for five days following a severe heart event had less inflammation than patients who didn't take the supplement.  Another recent study found that among patients with chest pain, those with low Vitamin D levels were more likely to die during the next two years than those with adequate levels of the nutrient.  While an association between low Vitamin D and cardiovascular disease risk is now clear, it is not known if taking Vitamin D can prevent these health problems. 

Researchers have also recently made progress in understanding how Vitamin D is important to the body’s capacity to fight infection.  For example, a recent study found Vitamin D plays a critical role in the body's ability to combat tuberculosis (TB) infection, a potentially fatal infection of the lungs. Investigators examined how the body tries to stop the growth of M. tuberculosis, the bacterium that causes TB. They found the white blood cells, or T-cells, that are critical to the body's ability to fight off infections, cannot function properly without adequate levels of Vitamin D.  The research report noted that the connection between low Vitamin D and infection may explain why darker skinned persons (whose skin is less effective at generating Vitamin D when exposed to the sun) are more susceptible to TB. 

How Much Vitamin D Do You Need?  This is still being debated by the medical community.  Recently, daily Vitamin D recommendations were increased.  For adults up to age 69 it is advised to take in 600 IU/day, and for those who are 70 or more the recommended intake is 800 IU/day. A level of 4,000 IU has been set as the maximum amount that is safe to consume daily, unless directed otherwise by your doctor.

Vitamin D Sources:  Vitamin D is naturally present in only a few foods.  Mushrooms, particularly those dried in the sun (containing approx. 400 IU per 3 oz. serving), and fatty fish such as salmon (approx. 800 IU in 3 oz.) and sardines are natural sources of Vitamin D.   Also, in the U.S. the milk supply is fortified with 100 IU of vitamin D per 1 cup of milk. Food manufacturers are also fortifying other foods such as yogurt, cereal, and orange juice.  The sun is an effective source of Vitamin D, but dermatologists recommend using sunscreen (which blocks vitamin D production) and getting vitamin D from food and supplements rather than risk exposure to the sun, which is associated with greater risk of skin cancer.  Supplements are also a useful way to boost your Vitamin D intake. 

What to do:  Consume food sources rich in Vitamin D such as lowfat/nonfat milk and oily fish such as salmon.  Also, next time you get blood work with your regular doctor, you can request your Vitamin D level be checked.   This way you can know if you are deficient or not and how much to supplement with.  At our clinic we usually recommend patients take 800-1000 IU of Vitamin D3 (another form, vitamin D2, is less well used by the body).  Vitamin D3 is widely available in multivitamins, combined calcium and vitamin D supplements, and in stand-alone Vitamin D supplements.  To maximize bone health benefits, it is best to take Vitamin D along with Calcium.  Persons with some conditions such as sarcoidosis should not supplement with Vitamin D so it is always best to check with your doctor before starting supplementation.

Adapted from information found at http://www.nlm.nih.gov/medlineplus/news/fullstory_118730.html & http://yourlife.usatoday.com/health/story/2011-10-03/Is-the-sunshine-vitamin-good-for-the-heart/50647202/1  and from news releases from University of California, Los Angeles (Oct. 12, 2011) & American Heart Association (November 15, 2011).