Our diet can greatly impact the effectiveness of supplements we take, by either increasing or decreasing their absorption and bioavailability. The question is how we can use this knowledge to avoid losing supplement absorption and make the best of it?
In short, it's best to take fat-soluble supplements with fats when you eat, and water-soluble ones with water on an empty stomach. Avoid taking supplements with high-fiber meals. Take synergistic compounds together, and find out what the is the best available form of the supplement you want.
Keep reading the article and learn more about diet and supplements in more detail!
What is bioavailability?
Bioavailability of supplements refers to the amount of supplement that actually gets absorbed in the bloodstream after you take it. It's not uncommon that only 50% (or less) of your supplement is absorbed when you take it (1). Because of that, we want to give you some tips on how to enhance the bioavailability of supplements, especially when it comes to your diet.
You probably already heard some instructions on how to take your medicine when it comes to food, and it's usually very important whether you take it before, during, or after your meal. The same can be said about supplements, as you essentially take them as an added bonus to your already existent diet pattern.
Always remember that your diet should be properly balanced to be your primary source of nutrients, vitamins, and minerals. Dietary supplements, as their name says, should always come second to the diet.
Factors affecting bioavailability
Other than food, some important factors affect the bioavailability of supplements, making it a rather complex issue (2). These are:
- Formulation - Some supplement formulations, like liquids, powders and liposomal supplements are more easily absorbed than pills, capsules, or tablets.
- Solubility - Fat-soluble supplements (vitamins A, D, E, K, resveratrol, coenzyme Q10) should be taken with fatty meals, while water-soluble supplements (vitamins of the B-complex and C) can be taken with water and generally have a higher bioavailability.
- Absorption in the digestive tract - The pH of the stomach affects how well certain nutrients are absorbed. For example, a highly acidic environment is necessary for the absorption of minerals like calcium and iron.
- Liver and digestive health - Conditions like Crohn's disease or irritable bowel syndrome can affect the abilities of your digestive tract to absorb all nutrients and supplements. Liver is needed for the proper metabolization of drugs and supplements, and certain liver issues and diseases can significantly lower the amounts of proper absorption.
- Age - The absorption of supplements and nutrients may decrease as you age. Also, men and women might absorb certain supplements differently, like iron, calcium, and magnesium.
Read more about the importance and meaning of bioavailability in our article: "Bioavailability of Supplements – Meaning and Importance".
How does food affect bioavailability of supplements?
The story of how our diet affects bioavailability of supplements is a little more complex than just "take fat-soluble vitamins with fatty foods".
Today, we certainly know much more than we knew before, but a lot of scientific research will have to be done in the future to understand all the little nuances between our digestive system, foods we eat, and supplements we take.
However, the answer to this question can be summarized into a couple of factors:
1. Fiber slows down the absorption of supplements
Dietary fiber, particularly soluble fiber, can bind to minerals (like calcium, iron, and magnesium) and form complexes that are not easily absorbed by the intestines.
Fiber can also slow the absorption of other nutrients, including fats and carbohydrates, which can reduce the absorption of fat-soluble vitamins and other supplements (3).
2. Gut microbiota sometimes helps, sometimes not
Gut microbiota is a common name for all the microorganisms that live in our intestines and helps us metabolize foods and produce some vitamins. These tiny organisms can significantly enhance the absorption of some supplements. However, they can sometimes also eat and reduce the absorption of supplements (4).
For example, polyphenols from fruits, teas, and berries, are metabolized by gut microbiota. Depending on which of the bacteria and yeasts you have more in your gut, the bioavailability of those polyphenols can either increase or reduce.
In conditions like small intestinal bacterial overgrowth (SIBO), bacteria can consume vitamin B12, reducing its availability for absorption by the host. This can lead to deficiencies despite adequate supplementation. In these cases, iron absorption could also be decreased, as bacteria tend to take it for themselves.
Read more about the gut microbiota and its connection to longevity in our article: "Probiotic Supplements and Their Connection to Longevity".
3. Increased blood flow in the digestive system helps
When we eat and our stomachs are full, the emptying of the stomach will take some time. This can really decrease the absorption of some quickly soluble supplements you're meant to take on an empty stomach with water (5). On the other hand, that might benefit the sustained-release formulations, as is the case with some medicines as well.
On the other hand, when we eat, the digestive system's blood flow will increase. The higher amount of blood will help the intake of nutrients, and, you guessed it, supplements. Complex molecules found in supplements, especially probiotics and fat-soluble vitamins, will therefore benefit from you eating a meal and then taking them.
4. Food and supplement synergy and competition
Some supplements are absorbed better when taken with other specific foods. More on that below.
However, certain foods and supplements can be in competition as well. For example, if you take a lot of magnesium and calcium at the same time, they will compete for the same binding sites, and the absorption of both will be low. Also, vitamin C enhances the absorption of iron, but calcium decreases it.
Tips on improving supplement absorption
Given what we know so far, here are some tips on how you can optimize the bioavailability and absorption of the supplements you take. After all, we all want our supplements to be absorbed and do their thing. Nobody wants to waste a carefully chosen quality product.
1. Consider different forms of supplements
One of the most notable things about supplements is in how many different shapes and sizes they come. Usually, whey proteins are always in powder or liquid form, and vitamins are in pills or capsules.
Naturally, you can often find the same supplement in more than one form. So, the question is, what is the best supplement form for bioavailability? The answer is not so straightforward here either.
However, here are some of the best forms of supplements for increased bioavailability (6):
- Chelated minerals or liposomal preparations can be more bioavailable than standard forms because they resemble actual food better than pure chemical preparations.
- Liquid or powder supplements offer faster absorption than pills or capsules, especially for people with digestive issues.
2. Time your meals
In this case, choosing the right timing means correctly timing the intake of your supplement depending on when you eat. Some supplements absorb better when taken independently of meals, while others benefit from being taken with a meal.
Here is what we can gather from scientific research on supplement timing so far:
- Take fat-soluble vitamins with meals - take vitamins A, D, E, and K, resveratrol, and coenzyme Q10 with a fatty meal. Since they are fat-soluble vitamins and supplements, they will be absorbed much better when surrounded by fats (2).
- Don't take supplements when eating high-fiber meals - don't take your supplements if you just ate or you're about to eat a high-fiber meal (containing lots of veggies or legumes). Instead, take your supplement in between your meals, at least 2-3 hours later/before your next high-fiber meal (3).
3. Take supplements with synergistic foods
Some supplements will be absorbed much better when taken together with certain foods. Those foods are named "synergistic" for that reason. There are quite a few proven examples (7), such as:
- Iron and vitamin C,
- Curcumin/turmeric and pepper,
- Vitamin K and vitamin D,
- Vitamin B9 and vitamin B12,
- Omega-3 fatty acids and high-antioxidant foods like berries, nuts, and seeds,
- Zinc and protein-rich foods like meat, beans, and nuts,
- Calcium and vitamin D,
- Magnesium and prebiotic foods like garlic, onions, bananas, oats, and whole grains,
- TMG (betaine) and nicotinamide mononucleotide (NMN).
Conclusion
We went through a long and complicated list of ways in which food you eat can affect the efficacy of supplements you take. But, what we can note is that by sticking to the instructions on the label, you can already significantly enhance the absorption of your supplements.
Take fat-soluble supplements with fats when you eat, and water-soluble ones with water on an empty stomach. Take synergistic compounds together, and find out if your supplement comes in a liposomal or liquid form, as those are the best forms.
Reference list:
- 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.
- Ofoedu CE, Iwouno JO, Ofoedu EO, Ogueke CC, Igwe VS, Agunwah IM, Ofoedum AF, Chacha JS, Muobike OP, Agunbiade AO, Njoku NE, Nwakaudu AA, Odimegwu NE, Ndukauba OE, Ogbonna CU, Naibaho J, Korus M, Okpala COR. Revisiting food-sourced vitamins for consumer diet and health needs: a perspective review, from vitamin classification, metabolic functions, absorption, utilization, to balancing nutritional requirements. PeerJ. 2021 Sep 1;9:e11940. doi: 10.7717/peerj.11940.
- Ioniță-Mîndrican CB, Ziani K, Mititelu M, Oprea E, Neacșu SM, Moroșan E, Dumitrescu DE, Roșca AC, Drăgănescu D, Negrei C. Therapeutic Benefits and Dietary Restrictions of Fiber Intake: A State of the Art Review. Nutrients. 2022 Jun 26;14(13):2641. doi: 10.3390/nu14132641.
- Barone M, D'Amico F, Brigidi P, Turroni S. Gut microbiome-micronutrient interaction: The key to controlling the bioavailability of minerals and vitamins? Biofactors. 2022 Mar;48(2):307-314. doi: 10.1002/biof.1835.
- Said HM. Intestinal absorption of water-soluble vitamins in health and disease. Biochem J. 2011 Aug 1;437(3):357-72. doi: 10.1042/BJ20110326.
- Vu KT, Kim JE, Cho IH, Park NH, Kim JK, Chun YS, Koo YT, Lee SH, Paik DH, Shim SM. A pilot study on the effect of formulation and individual muscle mass on vitamin C absorption in randomized clinical study. J Food Sci. 2022 Jun;87(6):2757-2765. doi: 10.1111/1750-3841.16169.
- Townsend JR, Kirby TO, Sapp PA, Gonzalez AM, Marshall TM, Esposito R. Nutrient synergy: definition, evidence, and future directions. Front Nutr. 2023 Oct 12;10:1279925. doi: 10.3389/fnut.2023.1279925.
