What Supplements Should Men Over 40 Take?

Man reading labels on supplement bottles at a kitchen counter

Most men over 40 need very few supplements. The ones with solid evidence for a healthy Canadian man are vitamin D (at least through the winter, and daily once you’re over 50), vitamin B12 from fortified foods or a supplement once you’re over 50, and creatine monohydrate if you strength train. Protein powder is a convenient food, not a necessity. Multivitamins, magnesium and zinc are only worth it if your diet falls short.

Tier 1: Strong case for most Canadian men over 40

Vitamin D. Health Canada’s recommended dietary allowance for men up to age 70 is 600 IU a day, rising to 800 IU after 70, with an upper limit of 4,000 IU (Health Canada). Health Canada also recommends that adults over 50 take a 400 IU vitamin D supplement daily, as summarized by Osteoporosis Canada. Osteoporosis Canada notes that between October and March, Canadians make little vitamin D from sunlight. The vitamin D guide covers food sources and dosing in detail.

Vitamin B12 after 50. Health Canada’s reference tables note that 10 to 30% of older people may not absorb B12 well from food, and advise people over 50 to meet the RDA mainly through B12-fortified foods or a supplement containing B12. If you take long-term prescription medication, ask your pharmacist whether it affects how you absorb B12.

Tier 2: Useful if you train

Creatine monohydrate. At 3 to 5 g a day, creatine is the best-supported supplement for strength and lean mass, and the ISSN reports a strong safety record in healthy people (Kreider et al., 2017). It only helps if you lift. Full details are in the creatine guide.

Protein powder. Not a supplement in the medical sense, just a convenient protein source. Use it when food can’t get you to your target. The protein powder guide explains when it’s worth buying.

Tier 3: Only if your diet falls short

Multivitamins. In 2022, the US Preventive Services Task Force concluded that evidence is insufficient to judge whether multivitamins prevent heart disease or cancer, and recommended against beta carotene and vitamin E supplements for that purpose (USPSTF, 2022). A basic multivitamin is reasonable insurance if your diet is narrow, but it’s no substitute for food.

Magnesium. Health Canada’s RDA for men 31 and older is 420 mg a day from all sources. The upper limit of 350 mg applies only to supplements and medications, not food (Health Canada). Most men who eat nuts, seeds, beans and whole grains get enough. If you supplement, stay at or below 350 mg.

Zinc. The RDA for adult men is 11 mg a day, with an upper limit of 40 mg. Meat, shellfish, dairy and legumes cover most men. The upper limit exists because more isn’t better, so check the label of any “men’s formula” stacking zinc on top of a multivitamin.

Tier 4: Skip or ask your doctor

Products marketed as testosterone or “male vitality” blends, fat burners, and proprietary blends that don’t disclose amounts have weak or no evidence and the highest risk of interactions. If you’re worried about energy, libido or mood after 40, that’s a conversation for your doctor, who can test rather than guess.

The summary table

Supplement	Who it’s for	Typical amount	Evidence
Vitamin D	All men in winter; daily for men over 50	400 IU supplement over 50; under 4,000 IU total	Strong for bone health; Canadian guidance
Vitamin B12	Men over 50	Fortified foods or a supplement	Health Canada advice for over 50
Creatine monohydrate	Men who strength train	3 to 5 g a day	Strong for strength and lean mass
Protein powder	Men who can’t hit protein with food	1 scoop as needed	Works as food
Multivitamin	Narrow or restricted diets	As labelled	Insufficient for disease prevention
Magnesium	Low intake of nuts, seeds, legumes	Up to 350 mg from supplements	Only if your diet is low
Zinc	Rarely needed	Up to 40 mg total	Only if your diet is low

How to buy supplements safely in Canada

Look for an NPN. Health Canada licenses natural health products and gives each one an eight-digit Natural Product Number. You can look it up in the Licensed Natural Health Products Database.
Choose single ingredients. You’ll know exactly what and how much you’re taking.
Ask your pharmacist. A pharmacist can check a supplement against your prescriptions and flag interactions before you buy.
Ignore promises. Anything claiming to “boost” hormones, melt fat or turn back the clock is a marketing claim, not evidence.

What to buy, and what to skip

Get vitamin D, B12 if you’re over 50, and creatine if you lift. Spend the rest of your supplement budget on food: more protein, more vegetables, better sleep. If you want a coach to review what you’re taking alongside your training and diet, and refer you to a doctor or pharmacist when something is outside coaching scope, that’s part of monthly 1:1 coaching.

Questions people also ask

Should a man over 40 take a multivitamin?

It's optional. The US Preventive Services Task Force found insufficient evidence that multivitamins prevent heart disease or cancer. A basic one won't hurt most men, but it doesn't replace eating vegetables, fruit and whole grains.

Is magnesium worth taking for sleep or muscle cramps?

Only if your diet is low in magnesium-rich foods such as nuts, seeds, legumes and whole grains. Health Canada sets the upper limit for magnesium from supplements at 350 mg a day; above that, diarrhea is common.

What does NPN mean on a supplement label?

It's Health Canada's eight-digit Natural Product Number. It means the product has been licensed and assessed as safe, effective and of good quality for its labelled use. Avoid products without one.

Do I need omega-3 supplements if I eat fish?

Fatty fish such as salmon, trout and sardines are food sources of omega-3 fats, so if you eat them regularly there's less reason to add a capsule. If you don't eat fish, or you have heart disease, ask your doctor or pharmacist whether one makes sense for you.

What Supplements Should Men Over 40 Take? The Evidence, Ranked