Responding to the Reader
Vitamins and minerals
What is the safest and most effective way to take vitamins and minerals?
Story by Laura Ly/Illustration by Aaron Leighton
About this feature
Alberta Innovates – Health Solutions frequently receives letters requesting information about Alberta research or about various medical conditions. "Responding to the reader" is a Research News feature intended to provide up-to-date information related to readers' questions, with the help of experts in the Alberta research community. Alberta Innovates – Health Solutions cannot provide medical advice, however; please consult your family physician about your specific health concerns.
Vitamin A, vitamin B-1, vitamin B-2, calcium, iron, and magnesium are just a few of the available vitamin and mineral supplements in health food stores and pharmacies. We know that vitamins and minerals in supplements and in our diet benefit our health, but can vitamins and minerals become harmful? Should we know more information about the effect of vitamins and minerals on our bodies? Dr. Sunita Vohra, an expert in complementary and alternative medicine, provides insight into how to optimize the benefits of vitamins and minerals, and avoid adverse effects.
“Anything that has the capacity to help also has the capacity to harm,” cautions Dr. Vohra. Supplements are used to supply our bodies with the necessary levels of vitamins and minerals to function properly, but taking supplements in excess, mixing several supplements together, or taking supplements with some medications can cause adverse effects. “The likelihood of having an adverse or harmful effect increases exponentially as the number of products you take increases,” explains Dr. Vohra. People should be more cautious when mixing supplements or taking them with other medication. “It’s not a question of A is safe, and B is safe, so I’ll just mix them. You don’t actually know that A plus B is safe.”
In certain cases, mixing supplements with medication can interfere with or reduce the body’s absorption of that medicine. For example, calcium is known to affect the absorption and uptake of certain medications—something to be aware of before taking your medication with a glass of milk or with your calcium supplement. “You may not be getting the intended benefit of your medicine because of the supplements you take at the same time. It’s not only important to review what you’re taking and how much, but when you’re taking it and what you’re taking it with,” notes Dr. Vohra.
“People tend to forget that food has active ingredients that can directly interact with medication and supplements,” says Dr. Vohra. The active ingredients in food can affect the bioavailability of vitamins and minerals. Bioavailability refers to the degree or rate in which a substance is absorbed or available for use by the body. “Various forms of supplements—iron or calcium, for example—have different amounts of bioavailability. You need less of substances that are more bioavailable; similarly, if you have something that is less bioavailable, you need larger quantities of it.”
The interaction between food, vitamins, and minerals also means that people can maximize the nutritional value of meals by pairing certain foods together. “The amount of nutrition your body can extract from food can vary depending on what you have with that food. For example, you can enhance the absorption of iron in red meat if you drink a glass of juice with your meal. The acidity of the juice promotes the meat’s bioavailability of iron,” explains Dr. Vohra.
People should also be careful about the types of vitamins they ingest. Excess levels of water-soluble vitamins, such as vitamins B and C, are excreted through the urine. However, fat-soluble vitamins—vitamins A, D, E, and K—are dissolved in fat cells and stored in the liver. As a result, fat-soluble vitamins are retained in the body and can be potentially dangerous if the vitamin levels build up over time. An overabundance of vitamins and minerals can result in hypervitaminosis, a type of vitamin poisoning.
Dr. Vohra suggests the safest source of vitamins and minerals is through food. “A general rule of thumb is that eating something in its natural state is better than taking a high dose supplement. For example, eating citrus-rich fruit is a healthier source of vitamin C than taking it as a pill.”
The safest and wisest approach to taking vitamins and minerals is to discuss supplement use with your healthcare providers—this includes anyone who provides you with health information such as physicians, nurses, pharmacists, naturopaths, or chiropractors. “Open communication about your health practices and the products you take is the safest way to optimize your health,” says Dr. Vohra.
“I wouldn’t recommend people use the internet as an information source. There is a profit-motivated industry behind some online information. Companies have a financial motive when recommending a particular vitamin or mineral, and that may not be the type of information you want to base your healthcare decisions on. You should get informed advice from a professional whose interests lie in your health and not in your pocketbook.”