Category Archives: Vitamin D

Vitamin D Deficiency and Muscle Function in UK Athletes


Researched published this month in the Journal of Sports Science suggests Vitamin D Deficiency is detrimental to musculoskeletal performance in UK athletes.

The researchers randomized 30 UK-based athletes and 30 age-matched healthy non-athletes into two groups, a vitamin D group (5,000 IU/day) and placebo. They assessed vitamin D status in both groups before supplementation.

The authors found that 62% of the athletes and 73% of the controls had vitamin D blood levels < 20 ng/mL. After supplementation, vitamin D status increased significantly from baseline mean 11 ng/mL to 41 ng/mL in the vitamin D group, with no significant change in the placebo group.

The vitamin D group demonstrated a significant increase in 10 meter sprint times (P = 0.008) and vertical jump height (P=0.008), with no change among the placebo participants.

The authors call for future studies using larger sample sizes. They conclude:

“The current data supports previous findings that athletes living at Northerly latitudes (UK = 53° N) exhibit inadequate vitamin D concentrations. Additionally the data suggests that inadequate vitamin D concentration is detrimental to musculoskeletal performance in athletes.”

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Dr Graeme L Close, lead author of the study said he and his team would like further research to investigate the optimum vitamin D dose for various tissues, providing evidence to encourage increasing the recommended daily allowance of D.

Source: Close GL, et al. Assessment of vitamin D concentration in non-supplemented professional athletes and healthy adults during the winter months in the UK: implications for skeletal muscle function. K Sports Sci. Oct 2012.


Support your immune system with Bio-Tech Vitamin D


Support your immune system with Bio-Tech Vitamin D

The children are back in school, temperatures are dropping, and the days are getting shorter. Optimal nutrition is more important than ever, but obtaining sufficient vitamin D from food and sun exposure alone can be difficult. Recent research indicates that vitamin D plays an important role in the body’s natural defense mechanisms.* For example, vitamin D receptors are present on certain white blood cells. Adequate vitamin D levels may be crucial to triggering these immune cells into action.* You can trust high-quality Bio-Tech vitamin D supplements to help you optimize your vitamin D levels and maintain a healthy immune system.

Common Cold

Patient Friendly Summary

Symptoms of the common cold include sniffles, postnasal drip and nasal obstruction, sneezing, and cough.

Risk factors

Risk factors for colds include:

  • Rhinovirus:  This is the most common virus, although others also cause colds.
  • Cold weather: Chilled nasal passages cannot fight viruses.
  • Contact with infected people:  Rhinovirus easily spreads from person to person.

Sunlight exposure and common cold risk

Colds are more common in winter. Ultraviolet-B (UVB) levels are lowest. Temperatures are also low. These same factors also contribute to influenza.

Vitamin D and common cold

Vitamin D levels

In one study, vitamin D levels of 38 ng/mL (95 nmol/L) were needed to significantly lower the risk of upper respiratory infections including colds.

How vitamin D works

Vitamin D may lower cold risk by:

  • Producing cathelicidin and defensins: These proteins have antibiotic properties. They reduce the risk of bacterial and viral infections.
  • Suppressing production of inflammatory compounds: Inflammation is a response of the immune system to fight infection.


The risk of the common cold and influenza was studied in postmenopausal African-American women living in New York. Women taking 2000 international units (IU) (50 mcg)/day of vitamin D3 (cholecalciferol) had a 90% reduction in either disorder. Those taking 800 IU (20 mcg)/day had a 60% reduction. Vitamin D3 is a form of vitamin D produced in the skin. It is likely that vitamin D had similar effects on both viral infections.


There are no reported studies of treating the common cold with vitamin D.

However, taking large doses of vitamin D at the beginning of infection, say 10,000 to 50,000 IU (250 to 1250 mcg)/day for 1 to 3 days, would increase vitamin D blood levels dramatically. Cathelicidin and defensin levels would also increase. Possibly these increases would reduce the severity and length of the common cold.


Patient friendly summary

Influenza is a viral infection of the lungs. There are many symptoms:

  • fever
  • body aches and muscle pain
  • headache
  • fatigue
  • dry cough
  • runny nose
  • dry or sore throat

The lining around the lungs may become inflamed. This can lead to bacterial pneumonia.

Risk factors

Influenza is most common in winter, a time when:

  • Solar ultraviolet-B (UVB) doses are low.
  • The weather is cold. This prevents white blood cells from reaching the lining of the respiratory tract and fighting the virus.
  • The humidity is low. Dry air allows the virus to live longer outside of the body.

Sunlight exposure and influenza risk

Influenza is more common in winter, when reduced sunlight causes vitamin D levels to fall.

Influenza rates peak in winter. There is less solar UVB light in winter, especially in areas farther from the equator. Thus, vitamin D levels are at their lowest.

Vitamin D and influenza

Vitamin D from sunlight or supplements reduces the risk of influenza.

Two randomized controlled trials found reduced incidence of influenza for those taking higher doses of vitamin D. A study involving African-American postmenopausal women in New York found a 60% reduced risk of colds and influenza for those taking 800 IU/d vitamin D3 and 90% reduced risk for those taking 2000 IU/d.

Another study in Japan, involving school children taking 1200 IU/d vitamin D3 vs. 200 IU/d, found a 67% reduction in Type A influenza, but no effect for Type B influenza. Type A influenza includes H1N1 varieties, which was the type involved in the 1918-19 pandemic influenza and the 2009 “swine flu” infections.

According to an observational study, vitamin D provides protection against influenza. This occurs when vitamin D levels in the blood are more than 38 ng/mL (95 nmol/L).

How Vitamin D works

To enhance the body’s immune system, vitamin D:

  • Produces cathelicidin and defensins—These proteins have antiviral effects to combat viruses.
  • Reduces inflammation—As a result, body temperature does not rise as much, and the lining of the lungs is less disturbed. This makes it harder for bacteria to give rise to pneumonia.


High levels of vitamin D may prevent or lower the risk of influenza. Vitamin D may also reduce symptoms of influenza and reduce the risk of developing pneumonia following influenza. Vaccines strengthen the body’s ability to fight infection. Therefore, combining high levels of vitamin D and anti-influenza vaccines provide the best protection.

Vitamin D

Based on several studies, raising vitamin D blood levels to 40 ng/ml (100 nmol/l) may reduce the risk of influenza. For most people, this involves taking 1000–5000 international units (IU) (25–125 mcg)/day of vitamin D during the influenza season.


Vitamin D3 and influenza

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On average, 2000-5000 IU/day vitamin D3 may provide protection against influenza. Vitamin D3, the true form of vitamin D, is produced in the skin. Larger doses of vitamin D taken for a short time strengthen the immune system. This allows the body to fight infection.

Peak Athletic Performance and Vitamin D

Dr. John Cannell

Dr. John Cannell

“No thanks Doc. I’m fine.”

“No way doc.” I had just finished informing my vitamin D deficient patient about the benefits of vitamin D, telling him he needed to take 5,000 IU per day. I used all the techniques I have learned in 30 years of medical practice to convince someone when proper treatment is needed. However, he knew that the U.S. government said young people need only 200 IU/day, not 5,000. He also knew the official upper limit was 2,000 IU/day. “What are you trying to do doc, kill me?”

Read the full article

Vitamin D: Wonder Pill for Top Athletes and the Rest of Us

Dr. L. Ray Mathews

Dr. L. Ray Mathews

Lynn Allison with Dr. L. Ray Matthews, Assistant Professor of Surgery, Director of Surgical Intensive Care Unit, Morehouse School of Medicine, Grady Hospital Atlanta

Martin Luther King Jr. High School in DeKalb County, Georgia, has an excellent football team, one of the best programs in the country, regularly sending players to top colleges.  But its success came at a high cost.  Like football players everywhere, injuries were a big problem — the teenagers suffered everything from torn ligaments, to broken bones, to concussions.  But suddenly, two years ago, the school, just east of Atlanta, reduced its sports injuries by an incredible 50 percent.  Its secret? The school started giving vitamin D supplements to its athletes.  The school embarked upon a parent-supported nutrition program that includes a daily regimen of vitamin D.  The program was instituted by Dr. L. Ray Matthews, director of critical care at Grady Hospital in Atlanta, and one of the nation’s leading researchers in vitamin D.

Protection from Injuries

Vitamin D — called the sunshine vitamin because it is produced when sunlight hits the skin — has been widely touted as important to overall health.  But recent studies and anecdotal evidence such as the Martin Luther King Jr. football team show that it can prevent and heal injuries — and not only in young people.  Vitamin D helps older people by increasing the absorption of calcium, which is very important for muscle strength and balance, which reduces falls.

Not Just for Athletes

Before his work with the football team, Dr. Matthews encouraged 11 friends and family members to be tested for their vitamin D levels.  All had low levels, he said.  “Before treatment, my mother had been having multiple falls,” he said.  She is dramatically improved since taking vitamin D supplements.  Dr. Matthews has also observed that his hospital patients heal faster when they take vitamin D.  “I take care of people in car crashes with broken bones, muscle weakness, infections and pneumonia,” he said.  “Vitamin D is an immune modulator.  It stimulates the immune system to fight off hospital infections.  Vitamin D helps to increase muscle strength in weak hospital patients.”  According to researchers at Harvard University, more than 70 percent of Americans have low levels of vitamin D, which puts them at increased risk of heart attack, strokes and 17 different types of cancer.  It also increases the risk for getting more colds and flu, muscle cramps and pain, chronic fatigue, depression, and seasonal affective disorder.  The U.S. Preventive Services Task Force recently issued new recommendations that adults at risk for falls take vitamin D.  The group found that 30 to 40 percent of people age 65 or older fall at least once a year, and five to 10 percent of them will suffer a serious injury such as a hip fracture.  “We are deficient in vitamin D because our society has changed from an agricultural and hunting culture to a technological indoor culture where we all stay inside.  These days, we don’t get the same exposure to sunlight as we did 50 years ago,” says Dr. Matthews.

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Get Tested

Dr. Matthews says that it’s imperative to get your vitamin D levels checked with a 25-hydroxyvitamin D blood test at your doctor’s office.  “Normal vitamin D level is 40-70 ng/mL,” he says. “For those who are low, I recommend a daily vitamin D3 supplement that ranges between 2,000 IUs and 5,000 IUs.”  Some foods like fatty fish and fortified milk and cereal also provide vitamin D.

D3Plus: The only Vitamin D on the market endorsed by the Vitamin D Council


Dr. John CannellHi, I’m Dr. John Cannell, founder and Executive Director of the 10-year-old nonprofit the Vitamin D Council and medical advisor to Bio Tech Pharmacal. I founded the Council knowing that a majority of the public is deficient in vitamin D.

To this day, my passion is vitamin D and my concern is vitamin D deficiency in the general public. I have written peer-reviewed scientific publications on the topic and have listed some of them below. My influenza and autism papers are some of the most all-time accessed papers in their respected journals.

Today, I am writing to you today to tell you about a relatively new product that Bio Tech Pharmacal has for sale called “D3Plus.” It is the only vitamin D on the market endorsed by the Vitamin D Council. Here at the Council, we spend a lot of time looking at vitamin D research and know the importance of a quality vitamin D supplement.

Every day we publish a short concise easy to read blog on the most recent vitamin D study in the medical literature and still we cannot keep up with all of the new remarkable studies. Most of them show some new benefit of vitamin D.

For example, today a study was published about the importance of vitamin D in human reproduction; yesterday, a study showed vitamin D helps prevent against some of the lung damages of smoking (still doesn’t mean you can smoke, however); and earlier this week, one study about vitamin D and diabetes. All of these findings were published in reputable medical journals. The “Vitamin D Era” is upon us. You may not know it, but you are living through the early part of that era.

Plain vitamin D will benefit you greatly if you take the correct amount, which is 5,000 IU per day for adults for the rest of your life, and 1000 IU/day/25 pounds of body weight for children. Pregnant and lactating women should take 6,000 IU/day, 5,000 for the woman and a 1,000 IU for the fetus or infant. Women who do this do not have to supplement breastfeeding babies with vitamin D, as their breast milk will have adequate quantities of vitamin D for the suckling infant. After weaning, the toddlers need vitamin D supplements.

However, to work properly in the body, vitamin D needs a number of cofactors:

  • Some of which Americans have in excess, such as vitamin A in the form of retinyl acetate or retinal palmitate or in cod liver oil (which should never be taken).
  • Some of which Americans probably are sufficient in, like most of the B vitamins, due to diet and the high use of multivitamins.
  • Some of which we do not get enough of. Vitamin D needs four cofactors that most Americans are often deficient in, sometimes seriously. I will explain how all four of these co-factors interact with vitamin D in your body.

The first is magnesium. The clear majority of Americans have inadequate intakes of magnesium, by itself a serious problem. Magnesium is involved in almost 300 chemical reactions in the body, including more than 10 involving vitamin D, including some reactions on DNA itself. Case studies imply magnesium deficient individuals do not always metabolize vitamin D properly. So take magnesium, at least 200 mg/day extra over and above diet, and eat vegetables, seeds and nuts as well.

The second needed cofactor is zinc, found in red meats, chicken, some seafood, whole grains, and dairy products. The total amount needed is contested. The vitamin D receptor located on your genome is like a glove, designed to grasp the vitamin D molecule so the vitamin D receptor complex can regulate the involved gene. At the base of the fingers of the glove sits a zinc molecule. Take at least 10 mg/day extra.

We know less about boron, also found in vegetables. We do know that it is involved in the cell wall actions of vitamin D; the rapid, non-genomic mechanisms. Some scientists believe that most Americans are boron deficient, again because they seldom eat enough vegetables. Studies show boron, on its own, helps joint health and increases testosterone secretion in men. The U.S. Department of Agriculture conducted an experiment on boron and postmenopausal women. The results showed that boron reduced excretion of calcium by over 40% in the kidneys, and helped activate vitamin D, suggesting a possible role in the suppression of osteoporosis. Take at least 2 mg/day of extra boron, besides what you get in your diet.

Finally, vitamin K2, which most Americans get little of, works with vitamin D to act like a police officer in the body, directing calcium to bone and away from arteries. Studies show that vitamin K2, on its own, helps bone health and perhaps heart health. It is very difficult to get from diet (small amounts in organ meats and hard cheeses) and is an expensive supplement. I recommend at least 80 mcg extra per day. The only food containing significant amounts of K2 is the fermented Japanese product called Natto. It is an acquired taste, to say the least.

The Vitamin D Council endorses D3Plus because it contains these four cofactors in amounts, that when combined with your diet, will be sufficient. Thus, a daily serving size of D3Plus (three capsules per day), will supply you with your 5,000 IU per day of vitamin D, plus all the cofactors to assure that you are getting the right amount of each cofactor (when combined with the usual American diet). Children can take fewer capsules based on their weight.

In my experience, many people feel better and do better on D3Plus than on regular vitamin D.

Feel free to contact me with questions.

John Cannell, MD Executive Director The Vitamin D Council



Selected bibliography:

1.  Cannell JJ, Vieth R, Willett W, Zasloff M, Hathcock JN, White JH, Tanumihardjo SA, Larson-Meyer DE, Bischoff-Ferrari HA, Lamberg-Allardt CJ, Lappe JM, Norman AW, Zittermann A, Whiting SJ, Grant WB, Hollis BW, Giovannucci E. Cod liver oil, vitamin A toxicity, frequent respiratory infections, and the vitamin D deficiency epidemic. Ann Otol Rhinol Laryngol. 2008 Nov;117(11):864-70. Review.

2.  Cannell JJ, Hollis BW, Zasloff M, Heaney RP. Diagnosis and treatment of vitamin D deficiency. Expert Opin Pharmacother. 2008 Jan;9(1):107-18.

3.  Cannell JJ, Vieth R, Umhau JC, Holick MF, Grant WB, Madronich S, Garland CF, Giovannucci E. Epidemic influenza and vitamin D. Epidemiol Infect. 2006 Dec;134(6):1129-40. Epub 2006 Sep 7. Review.

4.  Cannell JJ, Zasloff M, Garland CF, Scragg R, Giovannucci E. On the epidemiology of influenza. Virol J. 2008 Feb 25;5:29. Review.

5.  Cannell JJ, Hollis BW. Use of vitamin D in clinical practice. Altern Med Rev. 2008 Mar;13(1):6-20. Review.

6.  Cannell JJ. Autism and vitamin D. Med Hypotheses. 2008;70(4):750-9. Epub 2007 Oct 24.

7.  Cannell JJ. On the aetiology of autism. Acta Paediatr. 2010 Aug;99(8):1128-30. Epub 2010 May 19