Lower vitamin D levels associated with common cold
Lower vitamin D levels associated with common cold
An article published in the February 23, 2009 issue of the American Medical Association journal Archives of Internal Medicine revealed an association between lower levels of serum vitamin D and decreased resistance to upper respiratory tract infection (URTI), otherwise known as the common cold.Researchers at Massachusetts General Hospital, Children’s Hospital, Boston, and the University of Colorado analyzed data from 18,883 participants in the Third National Health and Nutrition Examination Survey (NHANES III) of U.S. participants aged 12 and older. Physical examinations following enrollment obtained blood samples and information including the occurrence of recent upper respiratory tract infections. Stored blood samples were analyzed for serum 25-hydroxyvitamin D levels.
Nineteen percent of the participants reported having a recent cold. For those whose serum vitamin D levels were lower than 10 nanograms per milliliter, the incidence was 24 percent, for subjects whose levels were 10 to less than 30 ng/mL the incidence was 20 percent, and the rate dropped to 17 percent among those with levels of 30 ng/mL or higher. After adjustment for demographic and other characteristics, those whose vitamin D levels were lowest experienced a 36 greater risk of URTI, and those whose levels were 10 to less than 30 ng/mL experienced a 24 percent greater risk compared with participants whose levels were at least 30 ng/mL. The association was significantly stronger for those with asthma.
The study is the largest and most nationally representative of its kind to date. “To our knowledge, this is the first population-based study to evaluate and demonstrate an association between serum 25-hydroxyvitamin D level and URTI,” the authors remark.
"The findings of our study support an important role for vitamin D in prevention of common respiratory infections, such as colds and the flu," concluded lead author Adit Ginde, MD, MPH, of the University of Colorado Denver Division of Emergency Medicine. "Individuals with common lung diseases, such as asthma or emphysema, may be particularly susceptible to respiratory infections from vitamin D deficiency."
"A respiratory infection in someone with otherwise healthy lungs usually causes a few days of relatively mild symptoms," explained senior author Carlos Camargo, MD, DrPH, of the Massachusetts General Hospital Department of Emergency Medicine. "But respiratory infections in individuals with an underlying lung disease can cause serious attacks of asthma or COPD that may require urgent office visits, emergency department visits or hospitalizations. So the impact of preventing infections in these patients could be very large."
"We are planning clinical trials to test the effectiveness of vitamin D to boost immunity and fight respiratory infection, with a focus on individuals with asthma and COPD, as well as children and older adults – groups that are at higher risk for more severe illness," Dr Ginde added. "While it's too early to make any definitive recommendations, many Americans also need more vitamin D for its bone and general health benefits. Clinicians and laypeople should stay tuned as this exciting area of research continues to expand."
The preceding was quoted from LifeExtension Update, Feb 25, 2009.
Taking supplements in the hope that they will reduce our chances of catching the common cold, or “boosting the immune system” remains among the top reasons that many people take vitamin and herbal supplements. Here is a study that provides a “robust” association between vitamin D and respiratory health. Those looking for scientific validation can take heart.
Vitamin D, of course, refers to two biologically inactive precursors - D3, also known as cholecalciferol, and D2, also known as ergocalciferol. Both D3 and D2 precursors are hydroxylated in the liver and kidneys to form 25- hydroxyvitamin D (25(OH)D), the non-active 'storage' form, and 1,25-dihydroxyvitamin D (1,25(OH)2D), the biologically active form that is tightly controlled by the body.
It is especially signigicant to note that, while low vitamin D levels were associated with increased risks of cold and flu in “healthy” people, the researchers noted that low levels were linked to even higher risks in people with chronic respiratory disorders, such as asthma and chronic obstructive pulmonary disease (COPD), and emphysema.
Commenting on the study, Andrew Shao, PhD, vice president, scientific and regulatory affairs, for the Council for Responsible Nutrition (CRN), a supplements trade association, said it adds to growth of science supporting the benefits of vitamin D.
“The majority of Americans continue to fall short in getting adequate amounts of vitamin D through diet alone. Given that vitamin D is relatively low in most foods, and there are serious risks associated with excessive sun exposure, dietary supplements are an important alternative to achieving a sufficient intake,” said Dr Shao.
“While this study on its own does not mean that higher vitamin D intake will ensure that you don’t get an upper respiratory tract infection this winter, it is consistent with, and adds to, the relatively new body of evidence showing that vitamin D plays a critical role in immune function.”
Does this mean that you should run out to Willner Chemists and buy yet another supplement? Not necessarily. It does mean that there is one more very good reason to make sure you are getting optimal levels of vitamin D in your supplement regimen. While 400 IU per day of vitamin D was thought to be adequate in years past, we now feel that two to three times that amount is better.
If you are taking a good, balanced multivitamin/multimineral supplement, you should be getting at least 400 IU there. Many multivitamin supplements have increased the level to as much as 800 IU or 1,000 IU. Check the label.
SuperNutrition, for example has from 700 IU to 1,000 IU in their various supplements.
Jarrow Formulas has a comprehensive multivitamin formula called “Multi 1-to-3” and it provides 1,000 IU in three tablets.
In Willvite, we have continued to maintain a level of 400 IU of vitamin D, but this is merely to provide maximum flexibility. Additional vitamin D would be recommended. Even if you suffer from osteoporosis, for example, and take Willvite and Bone Complex together, that would only add another 200 IU of vitamin D.
Does not mean you need a separate vitamin D supplement? Not necessarily. My wife and I rely on Willvite as the foundation of our supplement programs. We both also take an omega-3 (fish oil) supplement. Well, several of the companies that market fish oil supplements have now come out with fish oil - vitamin D supplements.
Nordic Naturals, for example, has a product called “Ultimate Omega-D3. This product supplies 650 mg EPA, 450 mg DHA, and 1,000 IU of vitamin D3 in two softgel capsules. Well, we used to take a regular EPA-DHA supplement anyway. So we just switched to this product, to satisfy the need for additional vitamin D.
No need for additional supplements--just a modification of what we were already taking.
Your supplement choices, by the way, should never be cast in stone. Things change. The science behind supplements changes. Your health changes. You age. This is why you should avail yourself of the consultation services at Willner Chemists. We are always happy to advise you relative to optimizing your supplement regimen.
Getting back to sources of vitamin D, if you are looking for a lower level of EPA-DHA, Nordic Naturals has that as well, in their regular “Omega-3D” product.
And for those of you who are aficionados of cod liver oil, that would be another way to increase your vitamin D level without adding an additional supplement. Just be sure to check the label of the cod liver oil product, as the amount of vitamin D can vary.
Nordic Naturals, for example, has two versions of their cod liver oil. The one called “Arctic-D Cod Liver Oil” contains 1,000 IU of vitamin D per teaspoonful. On the other hand, the regular “Arctic Cod Liver Oil” product in their line only contains 1-20 IU of vitamin D. That’s a big difference.
I’m using Nordic Naturals as an example, but there are many other quality lines available at Willner Chemists as well. Twinlab’s Norwegian Cod Liver Oil provides 462 IU of vitamin D per teaspoonful. Carlson Labs has a product, “Super D Omega-3,” that provides 2,000 IU of vitamin D per teaspoonful. I do not know exactly how much omega 3 is present, however.
NOW Foods has a Cod Liver Oil that contains from 180 to 450 IU of “naturally occurring” vitamin D per teaspoonful, along with decent amount of omega 3 oils and vitamin A.
Don Goldberg, R.Ph.