- Vitamin D is the big one in Canada: from about October to March, the sun is too low for your skin to make much.
- Health Canada’s recommended intake for most adults is 600 IU a day, with an upper limit of 4,000 IU.
- Magnesium, potassium and omega-3 are commonly low; iron and B12 matter for some groups.
- Test before megadosing; more isn’t better for most nutrients.
Most nutrients come from a varied diet, but a few are hard to get enough of in Canada, and heavy training increases needs for some. This guide covers the gaps that matter most for lifters, with Canadian guidance and how to check.
Vitamin D
At Canadian latitudes, ultraviolet light is too weak to make meaningful vitamin D in the skin for roughly half the year. Milk is fortified by law in Canada, and margarine and many plant milks are too, but many people still fall short in winter.
- Recommended intake: 600 IU a day for adults up to 70, 800 IU over 70 (Health Canada)
- Upper limit: 4,000 IU a day
- Test: 25-hydroxy vitamin D; coverage varies by province, and it’s available privately
Magnesium
Involved in muscle contraction, energy and sleep. Many Canadians eat less than recommended (about 400 to 420 mg for men, 310 to 320 mg for women). Sources: nuts, seeds, beans, whole grains, dark leafy greens.
Potassium
Supports blood pressure control and muscle function; most people fall short of about 3,400 mg (men) or 2,600 mg (women). Potatoes, beans, lentils, bananas and yogurt are good sources. See our electrolytes guide.
Omega-3 fats
EPA and DHA from fatty fish support heart health and help lower triglycerides, relevant for steroid users with poor lipids. Canada’s Food Guide encourages fish; canned salmon and sardines are affordable. Fish oil or algae oil are alternatives.
Iron
Women, vegans and endurance athletes are at higher risk of low iron. Steroid users usually aren’t, and testosterone raises red blood cells, so don’t take iron without a blood test showing you need it.
Vitamin B12
Essential to supplement on a vegan diet; absorption also declines with age and with some medications such as metformin.
What not to take blindly
- Iron without testing
- High-dose vitamin A, which can be toxic
- Multiple products containing the same nutrients, which can push you over upper limits
In Canada, look for a Natural Product Number (NPN) on the label, which shows Health Canada has reviewed the product.
Testing
Ask your family doctor about vitamin D, ferritin (iron stores), B12 and magnesium if you have symptoms or risk factors. Private testing is available at LifeLabs and Dynacare.
Frequently asked questions
How much vitamin D should Canadians take?
Health Canada’s recommended intake is 600 IU a day for adults up to 70 and 800 IU over 70, with an upper limit of 4,000 IU.
Can you get vitamin D from the sun in a Canadian winter?
Very little from about October to March, because the sun is too low.
Should lifters take a multivitamin?
A basic multivitamin is a reasonable insurance policy, but targeted nutrients like vitamin D and omega-3 matter more.
Do steroid users need iron?
Usually not. Testosterone raises red blood cells; only take iron if a blood test shows low stores.
This article is general information for adults in Canada, not medical advice. Talk to a doctor or pharmacist before using any prescription drug, anabolic steroid or research compound, and get bloodwork done. If you’re in crisis, call or text 9-8-8 (Suicide Crisis Helpline) any time.
