Event Review 


Review of Micronutrient Supplementation Continuing Education Event

by Coleen Nolan, MSc, PDt, Inner Peas Nutrition & Lifestyle Counselling



Last month I attended the DC-sponsored event: Micronutrient Supplementation- Minimizing Risks, Optimizing Benefits, by Liz da Silva MS RD, a clinical instructor at UBC. 


This presentation covered several areas, including:

  • Application of the Dietary Reference Intakes (DRI) in illness

  • Impact of bioavailability on applying DRI

  • Regulation of vitamin/mineral supplements

  • Prevalence of vitamin/mineral use

  • Case studies from acute and long-term care


Important points


  • Remember the Tolerable Upper intake level, or UL, applies to all sources of intake, and is important for several reasons, since exceeding UL has varying results:

    • Magnesium and Vit.C: diarrhea

    • Zinc:  copper deficiency

    • Vit. A & niacin:  hepatotoxicity

    • Folate:  masking B12 deficiency

    • Vit. D:  hypercalcemia


  • UL does not apply when treating deficiency


See the DRI tables at the NIH Office of Dietary Supplements http://ods.od.nih.gov/Health_Information/Dietary_Reference_Intakes.aspx


  • DRI key concepts- DRIs assume normal absorption, losses, processes

    • not a safeguard against deficiency

    • Not a prescription to treat deficiency

    • Not intake goals for individuals with disease, drug interactions or genetic mutations causing abnormal absorption


  • Bioavailability:

    • “The efficiency with which a dietary component is used systemically through normal metabolic pathways.” (Aggett 2010)

    • affected  by health status, drug-nutrient interactions, nutrient-nutrient interactions, chemical form (eg. Calcium carbonate needs acid environment vs. calcium citrate; use of certain medications impact nutrient status eg. Proton pump inhibitors affect several nutrients- calcium, B12, magnesium, iron; diuretics reduce thiamin levels)


  • Regulation of multivitamins in Canada

    • Natural Health Products Directorate (NHPD) assigns Natural Product Numbers (NPN)

    • Regulate amounts, based on minimum of 5% of Recommended Dietary Allowance (RDA)/Adequate Intake (AI) & max.= Upper Limit (UL)


  • Indications and contraindications for several nutrients (Vitamins D, B1, B12, calcium and iron), as well as safe supplementation practices, the RD role and resources.


This was a very informative session describing best clinical practices, based on current research.  The DC website will archive this material for future access.  There is another vitamin/mineral supplements online courseby Dr. Theresa Glanville currently available on the DC website, under ‘Learning on Demand’.

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