Understanding vitamin and mineral supplementation: What you need to know

I first met Janine in March 2006. An educated woman in her early 70s, she prided herself on staying informed about the latest nutrition trends by reading self-help books and following dietary advice from the internet, all in the hope of improving her health.

On our first meeting, Janine opened a fishing-tackle box revealing several layers and compartments that housed a pharmacy of supplements and herbal remedies. She weighed less than 100 lb, had a history of cardiovascular disease, suffered from osteoarthritis and osteoporosis and had the worst dowager’s hump (curvature of the spine causing a hump in the upper back) that I have seen. She was so frail, I feared she would fall and break into 100 pieces right in front of me!

Despite the fact that most days she complained of feeling physically ill, she insisted that the supplements she had taken over the years to stave off disease were her lifesavers. When asked for her definition of a healthy diet, she quoted a “nutritionist” she followed whose mantra to “eat minimally and supplement maximally for good health” was repeatedly emphasized in his highly marketed book. It was no surprise that her sage was also flogging his own “unique and potent” brand of supplements and making mountains of money through infomercials as well!

Janine started off small, intent on taking only a daily multivitamin, but over the years she progressively added one supplement after another to her routine, a practice we call “vitamin cocktailing.” Her daily supplement intake included zinc, magnesium, calcium, vitamins B6, B12 and D, chromium, gingko biloba, selenium, lutein and a concoction of mixed herbs. She was paying over $175 per month to support her habit, based on the advice of a person with no formal nutrition education. She was resolute in her belief that this was a small price to pay for an investment in her health. It was clear that Janine, caught up in the quagmire of “let me cure you” marketing, was buying hope in multiple bottles!

The vitamin epidemic

While Janine’s case may be an extreme example of vitamin cocktailing, recent research indicates that over 50 per cent of baby boomers take some form of vitamin or mineral tablet daily, with a third of Canadians aged 50 years and over combining vitamins, minerals and herbs regularly. With the media rampant with messages telling us that we need more supplements and herbal remedies to stave off illness, it’s no wonder there’s so much confusion about what we actually do need.

Most people understand that adequate levels of vitamins and minerals in the body help protect us against chronic disease and provide nutritional support. However, people are frequently under-educated about the actual function of nutrients and the importance of consuming vitamins and minerals from food.

Getting to the source

Fifty different nutrients from our natural food supply are required for health. Fruits, vegetables, meat, grains and dairy products naturally contain a synergistic combination of nutrients in a perfect balance that we cannot necessarily derive from a pill.

Many of us don’t consider vitamin and mineral supplements as “drugs,” yet that is exactly how they are classified by Health Canada and how we should regard them when considering their use. Taking supplemental nutrients may cause harm because single vitamins and minerals can increase or decrease the action or absorption of others. In addition, herbal products often aren’t regulated or backed by sound scientific proof to support their frequently inflated health claims. And added to this mix is the fact that many seniors take prescribed medications, the effect of which can be altered by supplements.

Eating a varied diet according to Canada’s Food Guide for Healthy Eating (CFGHE) ensures that you meet the dietary reference intake (DRI) for each nutrient (the daily amount required for good health). Taking a daily multivitamin tablet formulated for people over 50 may provide added “insurance” to maintain adequate nutrition, especially if you are not always following the CFGHE, and will do no harm to most seniors. However, keep in mind that dietary sources of nutrients are the most well digested and absorbed, and that taking more by tablet isn’t necessarily better and can in fact be harmful.

Let’s consider some of the most popular “nouveau” nutrients that are marketed to seniors and the pros and cons of taking each of them supplementally.

Vitamin B12

Our ability to absorb vitamin B12 from food diminishes with age. It is not uncommon for seniors to be deficient in vitamin B12, particularly those who eat poorly. This vitamin is required for making red blood cells (which carry oxygen throughout our body) and for proper nervous system functioning.

Vitamin B12 occurs naturally only in animal products, with the best source being meat. People over 50 should consider choosing a multivitamin supplement with more than 2.4 mcg of vitamin B12 if they are vegan, have a poor diet or if their bloodwork indicates a deficiency.

Vitamin C

The most highly recognized of the vitamins, vitamin C is abundant in citrus fruits, melons, leafy vegetables, peppers, broccoli and potatoes. North Americans can easily achieve the daily recommendation through the diet. The adult DRI for vitamin C is only 75 mg for women and 90 mg for men.

Smokers require additional vitamin C because each cigarette depletes tissue stores by up to 25 mg. That means that a pack-a-day smoker should supplement with 500 mg vitamin C above and beyond the DRI. Mega-dosing causes diarrhea and should be avoided by those with kidney disorders as it can cause kidney stones to develop.

If you choose to supplement with vitamin C, use a multivitamin with 50–100 mg per tablet to be on the safe side. Taking more vitamin C than your body needs produces the most expensive pee in town—any unused amount is excreted in urine and wasted.

Vitamin D

Our need for the “sunshine” vitamin in Canada increases after the age of 50, probably because seniors often avoid the sun during the summer and stay indoors more during the winter. Vitamin D is required for bone health and may lower the risk of colon cancer. The only substantial dietary sources are fortified milk, soy milk, egg yolk and some fish. Therefore, most dietitians advise those over 50 to supplement with 800 iu of vitamin D daily in addition to eating according to the CFGHE. Ensure that the supplement is vitamin D3, the active form of the nutrient.

Those who are taking anticonvulsive medications should also supplement because these medications interfere with vitamin D’s action in the body. There has recently been a lot of hype about possible links between vitamin D deficiency and multiple sclerosis and depression, with some advocates insisting that Canadians in general are deficient and should supplement with up to 4,000 iu per day. The verdict is still out on whether vitamin D can prevent these illnesses and other research suggests that over-supplementing may raise the risk of pancreatic cancer. Until more evidence from current clinical trials on vitamin D is released, you should avoid supplementing with more than 800 iu per day.

Protein powder

If you live in a developing country, you may require protein supplementation because of inadequate food supplies. In North America, however, we eat far more protein than we need.

Healthy seniors require an average of about 1–1.2 g protein per kilogram of body weight per day. That translates into 65–78 g each day for a 65 kg (143 lb) senior. You can consume 65 g of protein by eating a cup of oatmeal for breakfast (5.5 g protein), a salmon sandwich for lunch (27.5 g protein), a three-ounce chicken breast at dinner (28 g protein) and one tablespoon of peanut butter (4 g protein). And this list doesn’t include all of the other terrific sources of protein such as all meat and fish, milk, cheese, cereals, nuts, seeds and beans. Even broccoli has 2.6 g of protein per cup!

Beware of claims insisting that you require protein powder to maintain good health. Consuming adequate protein is essential for cell growth, repair and maintenance, energy and to maintain a strong immune system, but chronic overconsumption can affect kidney function and cause damage in people with existing kidney disease.

A scoop a day of whey powder can cost upwards of $80 a month and manufacturers often recommend taking three scoops per day, each with 20–25 g servings of protein. Add this to your regular diet and your kidneys are in for a workout! You should also consider that a 20–25 g serving of protein powder adds about 120–130 calories to your day. That means that supplementing with just one scoop per day in addition to your regular diet will cause you to gain 0.455 kg (one pound) every month!

Stick to the recommendations (1–1.2 g/kg/day) and eat according to the CFGHE.

Omega 3 fatty acids

These “healthy fats” are indeed a good addition to our diet, which is why the CFGHE recommends that Canadians consume at least two servings of fatty fish such as char, herring, mackerel, salmon, sardines or trout each week. These fish are rich in the most important omega 3 fatty acids: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).

Most Canadians don’t eat enough fatty fish. Therefore, a supplement containing EPA and DHA (not just ALA, which doesn’t provide the protective benefits of fish oil) is warranted.

However, because omega 3 fatty acids are blood thinning, they increase the risk of bleeding and certain types of stroke. People on blood-thinning medications such as warfarin (Coumadin) should avoid supplementation with omega 3 fatty acids altogether. Always check with your physician or dietitian prior to supplementation.


Lutein is an antioxidant that appears to play a specific role in reducing stress on the retina of the eye. Some studies suggest that it may be helpful in slowing age-related macular degeneration. However, there is no scientific evidence to support supplementing with additional lutein at this time.

Lutein is found abundantly in carrots, tomatoes, oranges, eggs and green leafy vegetables such as spinach, kale, Brussels sprouts, collard greens. It should not be required supplementally by those eating a varied and healthy diet.


Zinc is important for skin integrity, wound healing and general immune function. In clinical practice, I frequently prescribe 25 mg of zinc gluconate daily to aid in the healing of bed sores and skin ulcers in hospitalized patients. However, supplementation is discontinued as soon as the skin heals or after three months, whichever comes first.

The reason it is prescribed temporarily is that zinc and copper fight in the body. If there’s too much zinc in the blood, copper absorption decreases. We require copper for enzyme function and iron transport, so knocking out its action can cause other health problems.

Back to Janine

The supplements that Janine revered unfortunately caused some damage to her organ systems. It took two years just to rebalance her bloodwork after she pared down to a few safe supplements.

Janine began practicing due diligence when deciding whether to take a supplement, irrespective of whether it was a vitamin on the drug store shelf or an herbal remedy from a homeopath. She started assessing the credibility of her sources for nutrition advice, choosing only registered dietitians as her primary advisors, sought out only governmental or organizational websites for information and stopped believing every article and advert she read. Her hope and better health now comes from a getting accurate advice on what to eat and what supplements she actually needs.

It’s no longer a question of staying healthy. It’s a question of finding a sickness you like.
—Jackie Mason

Seniors most likely to require a daily multivitamin include those:

  • who don’t eat enough, eat a limited variety of foods or miss meals
  • with lactose intolerance, irritable bowel disease or celiac disease
  • who stay inside most of the day, and therefore have limited sun exposure
  • who eat a vegan diet
  • who abuse alcohol or smoke
  • who are recovering from surgery or have a chronic disease
  • who take medications that interfere with their appetite.

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