May 05, 2020



What Is the Canadian Integrative Medicine Association (CIMA)?

In 2015, CIMA was created as a network of Canadian physicians with special interest in integrative therapies. Integrative medicine includes all treatments that previously went under the heading of holistic medicine, alternative therapies, and complementary medicine. CIMA doctors have expertise in a large variety of medical therapies that are not taught in medical schools and can be used seamlessly alongside conventional treatments in everyday medical practice, whether it is in a private or hospital-based setting. CIMA does not accept any industry funding.



1. Can’t you get all the necessary vitamins from your food?

No. Not year round if the latitude is above 35o (and your skin is covered). That includes all of Canada.

Vitamin D status depends on diet, genetic makeup, digestion, medication interference, body weight, and environment. Even if some foods are fortified, Canadian diets do not contain adequate amounts of vitamin D3. It is necessary to have exposure to UVB sunlight to produce vitamin D3 in the skin and, during Canadian winters, this is impossible. Dark skin, sunscreen, working indoors or behind glass, clothing, thin skin and obesity will also interfere with vitamin D3 production, even in the summer.

Many essential nutrients are either not in our food (poor diet) or not well absorbed (e.g. acid suppressing medications, elderly with poor digestion). The body cannot manufacture essential vitamins, such as vitamin C, and requires higher doses of vitamin C under stress, either emotional or physical. That is why vitamin C supplementation helps fight off viral infections.

2.  Should all Canadians be taking vitamins and supplements?

Yes. As a minimum Canadian adults should take vitamin D3 4000 IU daily from October to May and continue year-round if their skin is not exposed to the sun in the summer months. Serum 25-(OH)VitD should be tested to determine if that dose is sufficient. This is consistent with recommendations from the International Society for Orthomolecular Medicine, the Institute for Functional Medicine, and the Multiple Sclerosis Society of Canada. Due to a statistical error, the Institute of Medicine mistakenly published their recommendation for vitamin D 800 IU per day, when in fact the corrected recommendation was 8000 IU per day.

Veugelers PJ et al. A statistical error in the estimation of the recommended daily allowance for vitamin D. Nutrients. 2014; 6(10) 4472-5.

Other vitamin supplements may or may not be needed depending upon factors such as food, stress, activity levels, and age. Often health can be made even better using supplements, even if, without them, a person’s general health might be considered “adequate”. Vitamin C is a good example, where supplementation can optimize health and well-being.


3. Why do you need sunshine to make the usable form of vitamin D? What exactly is Vitamin D3?

Vitamin D1 and D2 in our food are converted by UVB wavelength sunlight on the skin into vitamin D3. This 25-(OH)vitamin D is then converted by the liver into 1,25-di(OH)vitamin D, the active form in the human body. Sunlight exposure on the skin or supplementation with vitamin D3 is a necessity.

4. Why are the elderly more vulnerable to nutritional deficiency?

Elderly Canadians rarely get exposed to the sun, even in summer months, and their vitamin D3 stores are chronically depleted. Due to poor food intake and weakness of digestion, they are less likely to absorb important nutrients, which include vitamins and minerals. Often the elderly are taking medicines which can interfere with assimilation.

It is important to note that apparently healthy young Canadians can also have unsuspected vitamin deficiencies.

5. Can vitamins be toxic? Can children and pregnant women take vitamins?

Vitamin toxicity is rare and is far outweighed by the incidence of deficiency.

According to the Mayo Clinic, a person can take 80,000 IUs per day of vitamin D3 for several months without causing toxicity. The Multiple Sclerosis Society of Canada states that toxicity would require exceeding 30,000 IU/day over an extended period of time and serum 25-(OH)vitamin D levels over 500 nmol/l. Taking excessive doses of vitamin C orally can exceed the ability of the intestine to absorb this nutrient and cause loose stools. One then simply reduces the dose slightly. This is known as using “bowel tolerance” to measure a person’s current requirements for vitamin C, which may vary during infections. A good quality multivitamin will often supply sufficient daily zinc at 20 mg/tablet and higher doses for short periods are safe. With individual variations in absorption and tolerance of some nutrients, it is important to measure serum levels if possible, particularly with vitamin D3.

Vitamins are recommended for children and pregnant women.

6. What is the evidence for vitamin D3 deficiency in Canada?

There are 2 studies showing that Canadians, old and young, develop seasonal vitamin D3 deficiency and that there are a variety of factors that contribute to this.

While the incidence of deficiency was increased with age and non-white ethnicity, 42.2 % of non-white had serum 25-(OH)vitamin D concentrations less than 40 nmol/l, indicative of severe deficiency (normal >75 nmol/l; optimum>100 nmol/l).

Brooks S et al. An Analysis of Factors Associated with 25-hydroxyvitamin D Levels in White and Non--white Canadians. J AOAC Int. 2017; 100 (5): 1345-1054.

Vitamin D status and healthy young adults in fall and winter in the greater Toronto area showed an average 25-(OH)vitamin D concentration of 54.4 nmol/l in the fall and 38.4 nmol/l in the winter, confirming seasonal deficiencies (even in young adults!).

Gozdzik A et al. Serum 25-hydroxyvitamin D concentrations fluctuate seasonally and young adults of diverse ancestry living in Toronto. Health Canada 2017 survey.

Severe vitamin D3 deficiency is common in nursing homes and is an independent risk factor for mortality. To correct vitamin D deficiency in people >65 years of age often requires up to 10,000 IU/day for 2-4 months. Community-acquired pneumonia mortality increased in severe vitamin D deficiency (<30 nmol/l).

Boucher B. The problem of vitamin D insufficiency in older people. Aging Dis. 2012; 3 [4]: 313-329

Pilz S et al. Low 25-hydroxyvitamin D is associated with increased mortality in female nursing home residents. J Clin Endocrinol Metab. 2012;97(4):653-7

7. What is the evidence that vitamin D3 status affects the ability to fight infections, particularly the SARS-CoV-2 virus? 

Vitamin D3 plays two roles in immune function. The first is to increase the immune response when exposed to an infectious agent and the second is to modulate inflammation by controlling cytokine secretion. Vitamin D3 plays an essential role in preventing the uncontrolled COVID-19-triggered cytokine storm that appears to be killing patients in the ICU later in the disease process. Vitamin D deficiency also appears to be pro-thrombotic and causes abnormal blood clotting and bleeding.

The mean levels of vitamin D3 in 20 European countries correlate significantly and strongly with the number of cases and the mortality rates in COVID-19.

Ilie PC et al. The role of vitamin D in the prevention of coronavirus disease 2019 infection and mortality. Research Square prepublication. 2020.

In a small, retrospective observational study there was a suggested link between low vitamin D and severity of COVID-19 and also associated blood clotting and excessive bleeding. 100% of ICU patients less than 75 years old were deficiency in vitamin D.

Lau F et al. Vitamin D insufficiency is prevalent in severe COVID-19. Medrxiv. Prepublish.

Numerous epidemiological studies in adults and children have demonstrated that vitamin D3 deficiency is associated with increased risk and greater severity of infection, particularly of the respiratory tract. In a British study of 6789 subjects, higher vitamin D status at 45 years of age was associated with better lung function. In this study, each 10 nmol/l increase in baseline 25-(OH)vitamin D predicted a 7% reduction in respiratory tract infections.

Cameron F et al. The Role of vitamin D in Prevention and Treatment of Infection. Inflamm Allergy Drug Targets. 2013;12(4): 239-245

8. What about kidney stones with high dose Vit C?

In a 2018 study, no kidney stones were formed during 12 months of high-dose intravenous vitamin C treatment, even among the 8% of participants who reported a history of stones. Furthermore, renal function was not affected by vitamin C administration.

Melissa Prier et al., No Reported Renal Stones with Intravenous Vitamin C Administration: A Prospective Case Series Study, Antioxidants (Basel), 2018 May;7(5):68.

9. Is vitamin C deficiency common in Canadians?

In 2009, a study in Toronto of 979 non-smoking men and women age 20-29 years showed that 33% had sub-optimal and 14% had deficient levels of serum vitamin C.

Cahill L et al. vitamin C deficiency in a population of young Canadian adults.Am J Epidemiol. 2009;170(4):464-71

From the Health Canada Survey (2012)

Note: EAR is defined as the amount of nutrient that will meet the needs of one half the population; the other half being assumed to have inadequate intakes. So the percentage of Canadians who have inadequate intakes actually much higher than depicted by this graph.

10. What is the evidence for Vitamin C in preventing virus infections?

Vitamin C or ascorbic acid is an essential nutrient that must be acquired from the diet. It has many actions: anti-inflammatory, antioxidant, immune enhancing, and antiviral activity. Vitamin C is also required for the synthesis of collagen and without it people develop scurvy.

Ascorbic acid has been found to have a wide range of anti-viral properties. Early trials showed that vitamin C shortened the frequency, duration and severity of common colds.

A 2018 study of 56 patients with severe pneumonia given 6 g of oral vitamin C daily reported an 85% drop in mortality and double the rate of radiologic improvement in the lungs after one week of treatment.

11. What studies support the use of Vitamin C in treatment of sepsis?

In the large randomized CITRUS-ALI trial, the use of intravenous vitamin C (IVC) in septic patients reduced the mortality by 16.5%. In a previous trial, Marik (et al) showed an absolute mortality reduction of 30% (with hydrocortisone and thiamine).

In 5 trials including 471 patients requiring ventilation over 10 hours, an oral dose of 1 to 6 g per day of vitamin C shortened ventilation time on average by 25%.

12. What studies support the use of Vitamin C and COVID-19?

A randomized controlled trial in China demonstrated a 31.5% reduction in death, less inflammation and less time on a ventilator for COVID-19 patients. Ruijing Hospital in Shanghai reported no deaths in the first 50 cases of moderate to severe COVID-19 using intravenous vitamin C. People who received intravenous vitamin C had a hospital stay about 3-5 day shorter than other similar patients. There were no side effects reported any of the IVC treatments

13. Are studies going on at the moment?

A new clinical trial is underway, in Wuhan China, investigating IV ascorbic acid in the treatment of severe 2019-nCoV infected patients with pneumonia. (Investigators will treat 140 patients, with a placebo control group versus IV Vit C dosed at 24 g/d for 7 days).

Twenty-seven hospitals in New York, Wisconsin, Houston, and East Virginia are using intravenous vitamin C protocols. Houston Hospital reported 0 deaths. Dr. Paul Marik at East Virginia Medical School has reported no deaths in the first 30 COVID-19 patients in his ICU.

The number of patients successfully treated with a protocol that includes IV vitamin C continues to climb.

14.  When should vitamin C therapy be started in treatment of COVD-19.

Vitamin C should be started as soon as the patient presents with symptoms, particularly if short of breath and requiring oxygen. In many cases oral vitamin C may be sufficient in mild cases. However, in moderate and severely ill patients, intravenous vitamin C is desirable.

Cheng R. Can early and high intravenous dose of vitamin C prevent and treat coronavirus disease 2019 (Covid-19)? Medicine in Drug Discovery. 2020.

Marik,P. EVMS Critical Care COVID-19 Management Protocol. [Viewed May 2]

15. Where do you get zinc in your diet?

Zinc is an essential mineral present in some foods, such as red meat, seafood (especially shellfish), legumes, seeds, and yogurt, and as a dietary supplement. It has many functions in the human body and zinc is involved in the activity of approximately 100 enzymes and incorporated into more than 3000 metabolic proteins.

16. Are many people in Canada zinc deficient? What are the symptoms of zinc deficiency?

Zinc deficiency becomes more common in Canada with aging. A common symptom of zinc deficiency is diminution of smell and taste. The human body does not store zinc and a daily intake is necessary.

17. What is the mechanism of action and evidence for zinc in COVID-19 treatment?

Zinc may prevent coronavirus from entering into human cells and has a role in immune cell communication. It increases the function of innate immunity, killer cells and macrophages. Intracellularly zinc acts to disrupt viral RNA replicase within cells (stopping virus replication), but it requires a transporter, such as chloroquine, to carry it across the cell membrane.

"(PDF) Zn Inhibits Coronavirus and Arterivirus RNA ...." [Viewed Apr 11].

18. What do you get Magnesium from in your diet? Why do you need it to fight viral infections?

Magnesium is found in spinach, pumpkin seeds, avocado, legumes, leafy greens, and dark chocolate.

According to the 2012 Health Canada survey, “More than 34% of Canadians over the age of 19 consumed magnesium in quantities below the EAR, with the prevalence of inadequate intakes rising to greater than 40% in half the adult age and sex groups.” Studies estimate that 70 to 80 percent of those over the age of 70 are not getting the recommended amount of magnesium in their diet. It is important to note that these minimal daily requirements will prevent overt signs of disease, but they do not represent the requirement for optimal health.

Note: EAR is defined as the amount of nutrient that will meet the needs of one half the population; the other half being assumed to have inadequate intakes. So the percentage of Canadians who have inadequate intakes actually much higher than depicted by these numbers.

Magnesium is involved in more than 300 metabolic reactions in the body. Low magnesium levels are common in septic ICU patients and play a critical role in recovery. Magnesium modulates cells of the innate immune system, such as macrophages, as well as cells of the adaptive immune response including T lymphocytes.

Velissaris D et al. Hypomagnesemia in Critically Ill Sepsis Patients. J Clin Med Res. 2015;7(12):911-918.

Bilal M. Magnesium in the Modulation of Immunity. Article. 2020. [Viewed April 29]

19. Where do you get Selenium? Why do you need it to fight viral infections?

Selenium is found in Brazil nuts, tuna, oysters, pork, beef, chicken, tofu, whole-wheat pasta, shrimp, and mushrooms. However the amount of selenium in any product varies greatly with the selenium content of the soil in which it is grown/raised.

Recent studies have shown that the host immune response is affected by a diet deficient in selenium and the viral organism itself can alter its virulence in a host with selenium deficiency and associated oxidative stress. This change in the viral genome can make a normally benign and mildly pathogenic virus become highly virulent. Selenium deficiency can both increase susceptibility to infection and allow benign strains of Coxsackie, influenza, and possibly other viruses to mutate to highly pathogenic strains.

Beck M et al. Selenium Deficiency and Viral Infection. J of Nutrition. 2003. 133(5):1463-1467.

Steinbrenner H at al. Dietary selenium in adjuvant therapy of viral and bacterial infections. Adv Nutr. 2015;6(1):73-82.