Live in health with Dr. Sasha High

Vitamins & Supplements: What to take, what to skip, and why

Vitamins & Supplements: What to take, what to skip, and why
One of the number one questions I get asked is “Should I take a multivitamin?” or “What supplements should I take?” So I wanted to share my thoughts on vitamins and supplements, as well as a rationale for what I prescribe and take myself. Here are a few commonly prescribed vitamins, minerals and supplements and my thoughts on each.
  • Sun helps our bodies make Vitamin D. But most Canadians don’t get much sun exposure, particularly in the winter and many people can end up deficient or insufficient in Vitamin D.
  • Vitamin D is important to help our bodies absorb other minerals, like calcium. It has been found to reduce overall mortality and cancer mortality.
  • Do I take? Yes
  • Who should take? People with true deficiency, little sun exposure, elderly and those with a history of cancer.
    Evidence: Zheng Y, Zhu J, Zhou M, Cui L, Yao W, Liu Y (2013) Meta-Analysis of Long-Term Vitamin D Supplementation on Overall Mortality. PLoS ONE 8(12): e82109. doi:10.1371/journal.pone.0082109
    Evidence: Bjelakovic G1, Gluud LL, Nikolova D, Whitfield K, Wetterslev J, Simonetti RG, Bjelakovic M, Gluud C. Vitamin D supplementation for prevention of mortality in adults. Cochrane Database Syst Rev. 2014 Jan 10; 1:CD007470. doi:10.1002/14651858.CD007470.pub3.
  • Supplemental calcium is rarely necessary because most people get enough from their diet. Furthermore, excess calcium intake can cause kidney stones, cardiovascular disease
  • Evidence:
  • Most people do NOT need to be on routine iron supplementation, as iron can be obtained through a healthy diet. Supplemental oral iron can also cause GI upset.
  • Menstruating women can be at risk for iron deficiency due to blood loss.  Some may experience symptoms such as fatigue, restless legs syndrome, poor memory, or feeling cold. It is important to have your iron level checked with a simple blood test before starting supplementation.
  • Iron can be obtained through a healthy diet including dark green vegetables, oysters, fortified grain products and lean meat. Here is a list of foods with good iron content:
  • Do I take? Yes, because I have confirmed iron deficiency.
  • Who should take? Only if iron deficiency confirmed via blood test.
  • Microorganisms such as Lactobacillus and Bifidobacterium to help re-establish healthy bacteria in your intestines, called your gut microbiome.
  • Do I take? I am currently taking due to a change in my diet from travel and recent IBS symptoms but will stop after 6 weeks.
  • Who should take? Those with recent antibiotic use, international travel, changes in diet or living location, immune stress such as cold or flu, or irritable bowel syndrome.
  • Evidence:
  • Not a routine supplement required by the general public but Folic Acid should be taken by women of child-bearing age or those actively trying to become pregnant. Folic acid has bene proven to reduce neural tube defects in the developing fetus.
  • Do I take? Yes (you never know when Baby #2 will make his/her way!)
  • Who should take? Women of child-bearing age, people on the drug Methotrexate.
  • Evidence:


  • for the general population, eating oily fish like salmon and mackerel is a better source of polyunsaturated Omega 3 FAs (PUFAs) than supplementation.
  • pregnant women should consume 300mg/day to boost fetal brain development.
  • consensus on value of PUFAs in reducing cardiovascular disease, dementia, diabetes still inconclusive.
  • Do I take? No. I eat a lot of salmon and ground flax.
  • Who should take? Possibly those with increased risk of cardiovascular disease or those with hypercholesterolemia who do not wish to take statins.
  • Many people take a multivitamin in the hopes that it will make up for a sub-par diet. It won’t. There is no evidence that multivitamins have any benefit in regard to hard clinical outcomes, and they are considered not cost-effective.  Furthermore, the dose of the various vitamins/minerals within a multivitamin are often lower than required if true deficiencies exist.
  • Do I take? No.
  • Who should take? Probably no one. Maybe those who have had gastric bypass (although individual vitamin supplementation is likely better) or those with a very poor diet.
  • Evidence:
  • Evidence:
  • Evidence:
VITAMIN A, VITAMIN E and Beta-Carotene

2 thoughts on “Vitamins & Supplements: What to take, what to skip, and why”

    • Hi Janine – most people get sufficient vitamin C from vitamin B3 (niacin) from their diet and there is no good evidence for further supplementation. There may be rare situations in people who are malnourished (homeless, poor, etc) but not the average person.

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