Gerry K. Schwalfenberg

A review of the critical role of vitamin D in the functioning of the immune system and the clinical implications of vitamin D deficiency

This review looks at the critical role of vitamin D in improving barrier function, production of antimicrobial peptides including cathelicidin and some defensins, and immune modulation. The function of vitamin D in the innate immune system and in the epithelial cells of the oral cavity, lung, gastrointestinal system, genito-urinary system, skin and surface of the eye is discussed. Clinical conditions are reviewed where vitamin D may play a role in the prevention of infections or where it may be used as primary or adjuvant treatment for viral, bacterial and fungal infections. Several conditions such as tuberculosis, psoriasis, eczema, Crohns disease, chest infections, wound infections, influenza, urinary tract infections, eye infections and wound healing may benefit from adequate circulating 25(OH)D as substrate. Clinical diseases are presented in which optimization of 25(OH)D levels may benefit or cause harm according to present day knowledge. The safety of using larger doses of vitamin D in various clinical settings is discussed.

An estimate of the economic burden and premature deaths due to vitamin D deficiency in Canada

The objective of this work is to estimate the economic burden and premature death rate in Canada attributable to low serum 25-hydroxyvitamin D (25(OH)D) levels. Vitamin D deficiency has been linked to many diseases and conditions in addition to bone diseases, including many types of cancer, several bacterial and viral infections, autoimmune diseases, cardiovascular diseases, and adverse pregnancy outcomes. Canadians have mean serum 25(OH)D levels averaging 67 nmol/L. The journal literature was searched for papers reporting dose-response relationships for vitamin D indices and disease outcomes. The types of studies useful in this regard include randomized controlled trials, observational, cross-sectional, and ecological studies, and meta-analyses. The mortality rates for 2005 were obtained from Statistics Canada. The economic burden data were obtained from Health Canada. The estimated benefits in disease reduction were based on increasing the mean serum 25(OH)D level to 105 nmol/L. It is estimated that the death rate could fall by 37,000 deaths (22,300-52,300 deaths), representing 16.1% (9.7-22.7%) of annuals deaths and the economic burden by 6.9% (3.8-10.0%) or

Vitamin D Status of Clinical Practice Populations at Higher Latitudes: Analysis and Applications

14.4 billion (

Toxic Element Contamination of Natural Health Products and Pharmaceutical Preparations

8.0 billion-

Addressing vitamin D deficiency in Canada: A public health innovation whose time has come

20.1 billion) less the cost of the program. It is recommended that Canadian health policy leaders consider measures to increase serum 25(OH)D levels for all Canadians.

The Alkaline Diet: Is There Evidence That an Alkaline pH Diet Benefits Health?

Background: Inadequate levels of vitamin D (VTD) throughout the life cycle from the fetal stage to adulthood have been correlated with elevated risk for assorted health afflictions. The purpose of this study was to ascertain VTD status and associated determinants in three clinical practice populations living in Edmonton, Alberta, Canada - a locale with latitude of 53°30’N, where sun exposure from October through March is often inadequate to generate sufficient vitamin D. Methods: To determine VTD status, 1,433 patients from three independent medical offices in Edmonton had levels drawn for 25(OH)D as part of their medical assessment between Jun 2001 and Mar 2007. The relationship between demographic data and lifestyle parameters with VTD status was explored. 25(OH)D levels were categorized as follows: (1) Deficient: <40 nmol/L; (2) Insufficient (moderate to mild): 40 to <80 nmol/L; and (3) Adequate: 80–250 nmol/L. Any cases <25 nmol/L were subcategorized as severely deficient for purposes of further analysis. Results: 240 (16.75% of the total sample) of 1,433 patients were found to be VTD ‘deficient’ of which 48 (3.35% of the overall sample) had levels consistent with severe deficiency. 738 (51.5% of the overall sample) had ‘insufficiency’ (moderate to mild) while only 31.75% had ‘adequate’ 25(OH)D levels. The overall mean for 25(OH) D was 68.3 with SD=28.95. VTD status was significantly linked with demographic and lifestyle parameters including skin tone, fish consumption, milk intake, sun exposure, tanning bed use and nutritional supplementation. Conclusion: A high prevalence of hypovitaminosis-D was found in three clinical practice populations living in Edmonton. In view of the potential health sequelae associated with widespread VTD inadequacy, strategies to facilitate translation of emerging epidemiological information into clinical intervention need to be considered in order to address this public health issue. A suggested VTD supplemental intake level is presented for consideration.

The Benefits and Risks of Consuming Brewed Tea: Beware of Toxic Element Contamination

Background Concern has recently emerged regarding the safety of natural health products (NHPs)–therapies that are increasingly recommended by various health providers, including conventional physicians. Recognizing that most individuals in the Western world now consume vitamins and many take herbal agents, this study endeavored to determine levels of toxic element contamination within a range of NHPs. Methods Toxic element testing was performed on 121 NHPs (including Ayurvedic, traditional Chinese, and various marine-source products) as well as 49 routinely prescribed pharmaceutical preparations. Testing was also performed on several batches of one prenatal supplement, with multiple samples tested within each batch. Results were compared to existing toxicant regulatory limits. Results Toxic element contamination was found in many supplements and pharmaceuticals; levels exceeding established limits were only found in a small percentage of the NHPs tested and none of the drugs tested. Some NHPs demonstrated contamination levels above preferred daily endpoints for mercury, cadmium, lead, arsenic or aluminum. NHPs manufactured in China generally had higher levels of mercury and aluminum. Conclusions Exposure to toxic elements is occurring regularly as a result of some contaminated NHPs. Best practices for quality control–developed and implemented by the NHP industry with government oversight–is recommended to guard the safety of unsuspecting consumers.

Vitamin D, Essential Minerals, and Toxic Elements: Exploring Interactions between Nutrients and Toxicants in Clinical Medicine

There is disturbing evidence of widespread vitamin D deficiency in many population groups, particularly within nations at high latitude. Numerous recent studies in the scientific literature associate vitamin D deficiency with a colossal increase in morbidity and mortality. Since Canada is at higher latitude, this review assesses the vitamin D status within the Canadian population. This review was prepared by assessing available medical and scientific literature from Medline, as well as by reviewing several books and conference proceedings. A standard 25(OH)D level of 75-80nmol/l or more was used to indicate vitamin D sufficiency. Between 70% and 97% of Canadians demonstrate vitamin D insufficiency. Furthermore, studies assessing 25(OH)D levels of vitamin D at 25-40nmol/l reveal that many Canadians have profoundly deficient levels. Repletion of vitamin D3 with 2000IU/day for those not receiving judicious sun exposure and those with no contra-indications would likely achieve normalized levels in more than 93% of patients, without risk of toxicity. Explicit directives regarding vitamin D assessment and management are urgently required.

Vitamin D supplementation in a nursing home population

This review looks at the role of an alkaline diet in health. Pubmed was searched looking for articles on pH, potential renal acid loads, bone health, muscle, growth hormone, back pain, vitamin D and chemotherapy. Many books written in the lay literature on the alkaline diet were also reviewed and evaluated in light of the published medical literature. There may be some value in considering an alkaline diet in reducing morbidity and mortality from chronic diseases and further studies are warranted in this area of medicine.

Estimated economic benefit of increasing 25-hydroxyvitamin D concentrations of Canadians to or above 100 nmol/L

Background. Increasing concern is evident about contamination of foodstuffs and natural health products. Methods. Common off-the-shelf varieties of black, green, white, and oolong teas sold in tea bags were used for analysis in this study. Toxic element testing was performed on 30 different teas by analyzing (i) tea leaves, (ii) tea steeped for 3-4 minutes, and (iii) tea steeped for 15–17 minutes. Results were compared to existing preferred endpoints. Results. All brewed teas contained lead with 73% of teas brewed for 3 minutes and 83% brewed for 15 minutes having lead levels considered unsafe for consumption during pregnancy and lactation. Aluminum levels were above recommended guidelines in 20% of brewed teas. No mercury was found at detectable levels in any brewed tea samples. Teas contained several beneficial elements such as magnesium, calcium, potassium, and phosphorus. Of trace minerals, only manganese levels were found to be excessive in some black teas. Conclusions. Toxic contamination by heavy metals was found in most of the teas sampled. Some tea samples are considered unsafe. There are no existing guidelines for routine testing or reporting of toxicant levels in “naturally” occurring products. Public health warnings or industry regulation might be indicated to protect consumer safety.