There is an ongoing debate in the nutrition world: Is taking active ingredients as supplements that deliver a large dose better than eating them more through food that offers higher bioavailability? Or to put it differently, if someone ingests 500 mg of a nutrient from a supplement versus from food, which delivers it more effectively? We will try to answer this question in the form of case studies on magnesium, quercetin, and curcumin.
It seems the answer to that question is more individual and complex than we thought. Keep reading to find out more.
What is bioavailability?
If you've been keeping up with us, you know that we've talked about the bioavailability of supplements a couple of times so far. This time, we want to dive deeper into specific supplements we offer and their chances to end up where they need to in your body. However, to do this, we need one more short lesson in theoretical terms.
Bioavailability is the term used to describe the amount of nutrients present in food or in a supplement that our bodies are actively going to use. The higher the bioavailability of a product, the more of its active ingredient is going to be delivered to the desired part of the body and have an active effect there (1).
Bioavailability is only a subgroup of absorption, because not everything that is absorbed into the blood will be actively used by your body. If you want to know more, read our previous article:
What affects bioavailability?
Bioavailability of a certain active ingredient is incredibly complex and depends on many factors (2):
- Formulation (e.g., oxide vs. citrate for magnesium),
- The way of delivery (e.g., food, capsules, powders, liposomes),
- Solubility,
- Presence of activating or inhibiting molecules (e.g., fibers, fats, other active ingredients)
- Your gut and liver health, metabolism, age, sex, and genetics.
As you can see from this list, there are many ways in which an active ingredient can be affected and interrupted on its way to you. A fat-soluble ingredient will prefer to be eaten with fats, the citrate form of magnesium is better absorbed than the oxide one, and as you age, you will absorb the active ingredients more slowly.
One of the most important factors is the formulation of the active ingredient, or how it comes to you. It could be through food in its natural state, or it could be through some sort of a supplement matrix (in powders, gels, capsules, liposomes, etc). Some claim the best way is to obtain all active ingredients through food, some say it's actually through a higher dose of supplements.
This list of what influences an ingredient's bioavailability can go on and on, which will make the bioavailability of each active ingredient a story for itself. We decided to break down the bioavailabilities of three active ingredients into case studies of magnesium, quercetin, and curcumin. Keep reading to find out the best way to obtain these ingredients.
If you want to know more about how your diet influences the bioavailability of supplements, find our previous article here:
Is it better to take magnesium through food or supplements?
Magnesium-rich foods include spinach, almonds, pumpkin seeds, and whole grains. The magnesium here is bound to natural compounds and typically has a lower elemental concentration, but comes together with cofactors (like vitamin B6) that enhance absorption.
On the other hand, magnesium supplements come in different forms (3, 4):
- Magnesium oxide: High magnesium content but very low bioavailability (~4%),
- Magnesium citrate: Better absorption (~30%),
- Magnesium glycinate: Highly bioavailable and gentle on the stomach.
With supplements, you can easily take up to 400 mg of magnesium daily, which is the recommended dosage for adults. If you want to take that much through food, you will need to eat about 550 grams of cooked spinach, for example. As magnesium comes in many foods, it's not that difficult to obtain the appropriate dosage by eating magnesium-rich foods as well. So, what's the better option?
Food will offer you a slower and more sustained release of magnesium, accompanied by other synergistic nutrients like vitamin B6. However, if you work out a lot, can't sleep, or you're not sure that you're eating enough magnesium, you can take supplements. They deliver higher absolute doses, and the effect is pretty quick.
In our webshop, we offer the currently best-known form of magnesium supplements:
Read more about magnesium supplements on our blog:
- How to Take Magnesium Glycinate: Best Time, Forms, and Other Considerations
- Magnesium Supplementation
Is it better to take quercetin through food or supplements?
Quercetin is a plant flavonoid with antioxidant properties. Quercetin is abundant in onions, apples, capers, and leafy greens. In food, it's present as quercetin glycosides, which are more water-soluble and can be better absorbed in the gut than the plain supplement form.
As a supplement, quercetin is often delivered in:
- Plain quercetin aglycone: Poor absorption
- Quercetin phytosome or liposomal quercetin: Enhanced bioavailability (up to 20x better)
Food-based quercetin is more bioavailable than standard supplements. Some formulations, like phytosomes, can narrow the gap, but eating quercetin through whole foods like onions and apples is probably still more efficent than taking supplements.
With that said, quercetin is a rare and very valuable antioxidant that can reduce inflammation, keep your heart healthy, and support brain health. Even upping the dose a little through supplements is a good thing, especially if you don't want to eat plenty of raw onions and apples.
Approximately 100 grams of apples will have 4-5 mg of quercetin (especially red apple varieties) (5), while a medium-sized onion will have around 50 mg of quercetin (6). You can safely take up to 1000 mg of quercetin through capsule supplements per day, and even if you absorb only 20% of that (which is 200 mg), even that's way more than eating a whole onion or a kilogram of apples.
In our webshop, we currently offer the 99% pure quercetin powder supplements:
Read more about quercetin supplements on our blog:
- What is the optimal dosage of quercetin?
- Quercetin 101: Nutrition and Its Health Benefits
- Taking Quercetin: Dosage, Tips, and Other Considerations
Is it better to take curcumin through food or supplements?
Curcumin, the active compound found in turmeric, is famous for its poor bioavailability. This is because we metabolize and eliminate it very quickly. Piperine, an active ingredient in pepper, can enhance the bioavailability of curcumin by 2000%. This is why traditional foods and supplements usually contain it (7).
In traditional Indian cuisine, turmeric is cooked with fats and black pepper, which naturally enhance curcumin absorption. However, the actual dose in food is very low, often <100 mg per serving. This is why supplements always clearly outperform the intake through food.
Conclusion
If someone ingests 500 mg of a nutrient from food vs. a supplement, the answer of which is better heavily depends on the formulation and context. Supplements can offer precise dosing and targeted benefits, but whole foods offer nutrient synergy, better safety, and more effective real-world uptake.
Remember to always prioritize a balanced diet full of nutrients. This will keep you healthy and offer you plenty of nutrients, minerals, vitamins, and polyphenols in your daily life. It would be fairly unreasonable to think that you could take all the nutrients in the form of supplements, and you need all of them, at least in smaller amounts, daily. However, this will not give you very high doses of specific nutrients, unless you decide to eat copious amounts of certain foods, which is also not good for you.
Choose a high-quality supplement to experience all the health benefits of targeted therapy and high dosages of active ingredients. Do your research and find out what the best formulation of a certain supplement is for solubility and absorption, find out when and how to take it, and what the appropriate dosage is.
Combining these two approaches, through a healthy diet and targeted supplement intake, will offer you the very best you can get from the colourful world of nutrients.
Literature sources:
- Schümann K, Classen HG, Hages M, Prinz-Langenohl R, Pietrzik K, Biesalski HK. Bioavailability of oral vitamins, minerals, and trace elements in perspective. Arzneimittelforschung. 1997 Apr;47(4):369-80. PMID: 9150856.
- Smułek W, Kaczorek E. Factors Influencing the Bioavailability of Organic Molecules to Bacterial Cells-A Mini-Review. Molecules. 2022 Oct 4;27(19):6579. doi: 10.3390/molecules27196579.
- Brilli E, Khadge S, Fabiano A, Zambito Y, Williams T, Tarantino G. Magnesium bioavailability after administration of sucrosomial® magnesium: results of an ex-vivo study and a comparative, double-blinded, cross-over study in healthy subjects. Eur Rev Med Pharmacol Sci. 2018 Mar;22(6):1843-1851. doi: 10.26355/eurrev_201803_14605.
- Walker AF, Marakis G, Christie S, Byng M. Mg citrate found more bioavailable than other Mg preparations in a randomised, double-blind study. Magnes Res. 2003 Sep;16(3):183-91. PMID: 14596323.
- Nishimuro H, Ohnishi H, Sato M, Ohnishi-Kameyama M, Matsunaga I, Naito S, Ippoushi K, Oike H, Nagata T, Akasaka H, Saitoh S, Shimamoto K, Kobori M. Estimated daily intake and seasonal food sources of quercetin in Japan. Nutrients. 2015 Apr 2;7(4):2345-58. doi: 10.3390/nu7042345. PMID: 25849945; PMCID: PMC4425148.
- Kwak JH, Seo JM, Kim NH, Arasu MV, Kim S, Yoon MK, Kim SJ. Variation of quercetin glycoside derivatives in three onion (Allium cepa L.) varieties. Saudi J Biol Sci. 2017 Sep;24(6):1387-1391. doi: 10.1016/j.sjbs.2016.05.014. Epub 2016 May 27. PMID: 28855836; PMCID: PMC5562462.
- Prasad S, Tyagi AK, Aggarwal BB. Recent developments in delivery, bioavailability, absorption and metabolism of curcumin: the golden pigment from golden spice. Cancer Res Treat. 2014 Jan;46(1):2-18. doi: 10.4143/crt.2014.46.1.2.
