When it comes to supplements, the sheer volume of products on the market can make it difficult to know what actually works, what to look for in a quality product, and when supplementation is truly worth it. That is exactly why we believe it is so important to hear from physicians who are not only trained in evidence-based medicine but who also work with patients every day to address real nutritional gaps.

In this blog post, we will walk through some of the most important takeaways from the conversation we had with Authority Magazine about supplements, explore what the latest research says about commonly recommended supplements, and share practical advice for building a supplement routine that is actually backed by science. Whether you are brand new to supplementation or looking to refine your current approach, there is something here for you.

Note: This content is for informational purposes only and does not replace professional medical advice. Always consult a licensed healthcare provider before starting any new supplement.

Why Doctor Insights on Supplements Matter

The supplement industry in Canada is enormous. Valued at tens of billions of dollars, it continues to grow year over year as more Canadians look for ways to optimize their health beyond diet alone.

But here is the challenge: unlike prescription medications, supplements do not need to prove their safety or effectiveness before being sold to the public. This means the responsibility falls largely on the consumer to determine what is worth taking.

That’s why physician perspectives on supplements carry so much weight. Doctors like Dr. Mankaryous, who is also our Chief Medical Officer here at myrocky, can evaluate the scientific evidence while also understanding the biochemistry behind how supplemental nutrients are absorbed and used by the body.

In his Authority Magazine interview, Dr. Mankaryous emphasized that the best supplement routine is one that is intentional, targeted, and guided by someone who understands your unique health picture. Rather than grabbing whatever product is trending on social media, he encourages patients to work with a clinician who can connect the dots between symptoms, lab results, and nutritional needs.

Doctor-Approved Supplements: What Physicians Commonly Recommend

Vitamin D

Vitamin D is arguably the most frequently recommended supplement by physicians, and for good reason. It plays a critical role in immune function, bone health, mood regulation, and more.

A 2025 review published in Nutrients found that serum concentrations above 30 ng/mL are associated with significantly lower risks of major disease and mortality compared to levels below 20 ng/mL. Despite its importance, many Canadians remain deficient, especially those who spend the majority of their day indoors or live in northern climates with limited sun exposure.

Dr. Mankaryous noted in his interview that he typically pairs vitamin D with vitamin K2, which supports better calcium metabolism. This combination helps direct calcium to the bones rather than allowing it to accumulate in the arteries. It is a small adjustment that can make a meaningful difference in how your body uses the vitamin D you are taking.

Magnesium

Magnesium is another supplement that doctors frequently recommend. It is a critical cofactor in hundreds of enzymatic reactions in the body, supporting everything from energy metabolism and neuromuscular function to cardiovascular health and sleep quality.

A 2025 meta-analysis of 34 randomized controlled trials found that magnesium supplementation at a median dose of 368 mg per day led to significant reductions in both systolic and diastolic blood pressure.

One important point Dr. Mankaryous raised is that the form of magnesium matters. He shared an example of a patient taking magnesium oxide for months without improvement, who then switched to magnesium glycinate, a more bioavailable form, and noticed real benefits within weeks. This is a common scenario and a good reminder that not all supplement forms deliver the same results.

L-Glutamine for Gut Health

L-glutamine is a supplement that does not always get the attention it deserves. It is the primary fuel source for the cells lining the intestinal wall and plays a key role in maintaining gut barrier integrity. For individuals dealing with bloating, food sensitivities, or gut permeability issues, L-glutamine can be a helpful addition to a targeted routine.

Do Supplements Need to Be Third-Party Tested?

In short, yes. Third-party testing is one of the most reliable ways to verify that a supplement actually contains what the label says it does, and nothing that it should not.

Organizations like NSF International and USP (United States Pharmacopeia) run independent testing programs that evaluate supplements for identity, potency, purity, and the absence of harmful contaminants. While these certifications are voluntary in Canada, they represent a meaningful baseline of quality.

Dr. Mankaryous was firm on this point during his interview, calling third-party testing non-negotiable when choosing a daily supplement. He explained that two products can list the same ingredient on the label and deliver completely different results depending on their sourcing, formulation, and whether they have been independently verified.

For consumers, looking for seals from NSF, USP, or similar organizations is one of the easiest ways to filter out lower quality products.

How to Create a Supplement Routine That Actually Works

Building a supplement routine is not about stacking as many products as possible. In fact, Dr. Mankaryous cautioned against the idea that more is better. He explained that many vitamins and minerals compete with each other for absorption. Calcium and magnesium compete. Zinc and copper compete. Iron can interfere with the absorption of several other minerals. Taking a dozen things at once may actually reduce the benefit you are getting from each one.

Instead, the best approach to supplementation is targeted and intentional. Here are some practical steps to help you build a routine that is actually effective:

1. Start with bloodwork. Understanding your actual nutrient levels takes the guesswork out of supplementation. What works for someone else may not be what your body needs.
2. Identify your health goals. Are you focused on better sleep? Gut health? Energy? Longevity? Your goals should shape your supplement choices.
3. Choose quality products. Look for supplements that have been third-party tested by organizations like NSF or USP. Pay attention to the form of the nutrient, not just the ingredient name.
4. Consider timing and interactions. Some supplements are best taken with food, while others absorb better on an empty stomach. Spacing out competing minerals can also improve absorption.
5. Work with a healthcare provider. A licensed clinician can review your labs, understand your lifestyle, and recommend a routine built specifically for you. This is one of the most effective ways to get real results from supplementation.

What’s the Best Approach to Supplementation? Think Foundations First

One of the most memorable points Dr. Mankaryous made during his Authority Magazine interview was his analogy about building a house. He compared supplements to the finished work — the part that adds value and makes a difference — but only if the foundation is solid. That foundation includes whole foods, quality sleep, regular movement, and stress management.

This is a perspective that our medical team carries across all of our services. Supplementation works best when it is layered on top of a healthy baseline. A vitamin D supplement is more effective when you are also prioritizing sleep and outdoor activity. Magnesium does more for you when your stress is managed and your diet includes nutrient-dense whole foods.

Supplements are not a replacement for good habits. They are a way to fill the gaps that even the best habits cannot always cover.

Dr. Mankaryous also highlighted the importance of food literacy, noting that the modern food system is not always set up to support optimal health. Ultra-processed foods, depleted soil quality, and the convenience-driven nature of most diets mean that even people who eat reasonably well can show up with suboptimal nutrient levels. Supplements exist to bridge that gap, not to replace the effort of eating well.

When Should You Consider Adding Supplements to Your Daily Routine?

There are a few common scenarios where supplementation becomes especially helpful:

• You have a confirmed deficiency that shows up in your bloodwork. If lab results show low vitamin D, low iron, or suboptimal magnesium, supplementation alongside lifestyle changes is the most effective approach.
• You have specific health goals that food alone cannot fully address. For example, supporting mitochondrial function as you age or optimizing recovery from training may require doses that are impractical to achieve through food alone.
• You are addressing something that diet simply cannot fix. NAD+ is a good example. It is a coenzyme your cells need for energy production and DNA repair, and levels naturally decline with age. No amount of dietary adjustment will meaningfully raise NAD+ levels, which is where targeted supplementation becomes necessary.

The common thread here is intentionality. The best supplement routine is not the longest one. It is the one built around your actual needs, backed by evidence, and ideally guided by a healthcare professional.

References

1. U.S. Food and Drug Administration. “Dietary Supplement Products & Ingredients.” FDA.gov, U.S. Food and Drug Administration.
2. Grant, William B., et al. “Vitamin D: Evidence-Based Health Benefits and Recommendations for Population Guidelines.” Nutrients, vol. 17, no. 2, 2025, p. 277.
3. Asbaghi, Omid, et al. “Magnesium Supplementation and Blood Pressure: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.” PubMed, 2025.
4. NSF International. “Dietary Supplement and Vitamin Certification.” NSF, 2025.

Disclaimer: This article is intended for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your healthcare provider with any questions about a medical condition or treatment.

Editorial Standards: At Rocky Health, we’ve made it our mission to support men and women with trustworthy, easy-to-understand medical and health information online. Read more about our editorial standards here.