Vitamins & Minerals

Vitamins and minerals for athletes fall into two groups, each with a different purpose and taken at a different time. The first group consists of daily supplements: products you take in the morning with breakfast or in the evening to make up for deficiencies that arise more quickly during intensive exercise than with a sedentary lifestyle. Magnesium, omega-3, vitamin D, vitamin B complex and vitamin C are the most relevant daily supplements for endurance athletes. They support muscle function, the immune system, energy metabolism and recovery, and their effect is best with consistent daily intake over a longer period. The second group consists of electrolytes: mineral salts that the body loses through perspiration during intensive or long efforts and that you actively replenish during the training session or race itself.

The range covers both groups in full. For daily supplements there is magnesium in several forms (tablets, capsules and soluble powder), omega-3 fish oil softgels, vitamin D3, a vitamin B activation complex, vitamin C with immune support, probiotics for gut health, a concentrated vegetable powder and a multivitamin specifically tailored to athletes. For use during training there are electrolyte capsules and chewable electrolyte tablets that replenish sodium chloride, potassium, calcium and magnesium when you sweat. The choice per product depends on your training intensity, your daily diet, the season and the specific deficiencies you experience as an athlete.

Which supplements are there?

The range is divided into daily supplements for health and recovery and electrolytes for active use during training.

Magnesium

Magnesium is the most relevant daily supplement for virtually all intensive athletes. The mineral plays a role in more than 300 enzymatic processes in the body, including muscle contraction, nerve conduction and energy metabolism. Athletes lose magnesium through perspiration in considerably higher amounts than non-athletes, which means a deficiency can arise quickly with regular training. Magnesium is available in various forms: citrate and bisglycinate are absorbed best by the body and cause fewer stomach complaints than cheaper oxide variants. Magnesium as a drink powder is a fast way to take a higher dose in the evening before going to sleep, which also activates the sleep-promoting effect of magnesium.

Omega-3 fish oil

Omega-3 fatty acids (EPA and DHA) are polyunsaturated fatty acids that the body does not produce itself but has to obtain through food or supplements. For endurance athletes, omega-3 fatty acids are relevant because of their anti-inflammatory action: intensive training causes micro-inflammation in muscle tissue and joints, and a sufficient omega-3 status reduces recovery time and muscle soreness after hard training sessions. Omega-3 also supports cardiovascular health and joint mobility at a high training frequency. Softgels are the most concentrated format and the easiest to dose.

Vitamin D3

Vitamin D3 regulates calcium absorption for strong bones, supports the immune system and plays a role in muscle function. In the Netherlands, sun exposure from October to April is insufficient for production via the skin in virtually everyone who does not train outdoors for long periods every day. Athletes who mainly train early or late and catch little direct sun are also at risk of a vitamin D deficiency outside the winter months. Vitamin D3 is absorbed better in combination with a fat-rich meal.

Vitamin B complex and vitamin C

B vitamins play a central role in energy metabolism: they help convert carbohydrates, fats and proteins into usable energy for the working muscles. An active vitamin B complex is specifically formulated for people with a high energy requirement. Vitamin C supports the immune system and the production of collagen for strong tendons and joints. At a high training load the immune system is temporarily suppressed; extra vitamin C in powder form (soluble, quickly available) is particularly useful during intensive training blocks, the racing season or cold periods.

Electrolyte capsules and chewable electrolyte tablets

Electrolytes are mineral salts that the body loses through perspiration: sodium, potassium, calcium and magnesium. During efforts longer than 60 to 90 minutes at high intensity or in warm weather, a loss of electrolytes can lead to muscle cramps, reduced coordination and a loss of performance. Electrolyte capsules are specifically formulated to compensate for this loss and are taken with water during training or a race. Chewable electrolyte tablets are a practical alternative for use in transition zones or on the treadmill during a triathlon, where taking a capsule with water is more difficult. Capsules with caffeine are available as an extra option for the final phase of a long race.

Probiotics, greens, multivitamins and lactase

Probiotics are live bacterial strains that support the composition of the gut flora. A healthy gut flora improves the absorption of nutrients and strengthens the immune system, which in endurance athletes is regularly temporarily suppressed by a high training load. Concentrated vegetable powder is a supplement for athletes who eat too few vegetables and want to supplement their daily micronutrients with a single portion of powder. A multivitamin specifically for athletes covers several deficiencies at the same time at a maintenance level. Lactase is an enzyme that breaks down lactose and is only useful for athletes with lactose intolerance who want to eat dairy products or use dairy-based protein shakes without stomach complaints.

Which supplement suits you?

The most effective supplements are the ones that fill a concrete deficiency or need. Here are the most common situations.

You train several times a week and regularly suffer from muscle cramps, poorer sleep or fatigue that is not explained by the training load: start with magnesium as your first supplement. These are classic symptoms of a magnesium deficiency in intensive athletes. Choose a well-absorbable form such as magnesium citrate or bisglycinate in tablets or powder and take it in the evening before going to sleep. Expect an effect after two to four weeks of consistent use.

You do triathlon or endurance sport and want to compensate for electrolyte loss during long training sessions or races: add electrolyte capsules to your training nutrition. Take them during the bike or run for activities longer than 90 minutes in warm weather or at high effort intensity. Combine electrolyte capsules with isotonic sports drink or water, never with a caffeinated gel and a caffeine capsule at the same time, to prevent caffeine overdose.

You want to reduce muscle soreness after hard training sessions and protect your joints at a high training frequency: add omega-3 fish oil as a daily supplement. The anti-inflammatory action of EPA and DHA is strongest with consistent intake of at least 2 grams of EPA and DHA per day, spread over one or two intake moments with a fat-rich meal. Expect the most effect after four to eight weeks of regular use. For the combination with recovery nutrition, see also the muscle building and muscle recovery range.

You train in autumn and winter or you are regularly ill after hard training blocks: add vitamin D3 and vitamin C as seasonal supplements. In the Netherlands, vitamin D3 is relevant from October to April for almost everyone. Vitamin C in powder form is practical to take in periods of high load or if you notice that you are more susceptible to colds after hard training.

You have a busy lifestyle and want to keep supplements simple with one product that covers several needs: a multivitamin specifically for active athletes is a simple starting option that supplements the most relevant vitamins and minerals at a maintenance level. It is not a replacement for targeted supplements in the case of known deficiencies, but it covers the basics for athletes who do not want to choose each supplement separately.

Electrolyte capsules or chewable electrolyte tablets?

Both products deliver the same electrolytes but differ in form of administration, timing and ease of use.

Electrolyte capsules are swallowed with water. They are precisely dosed and easy to carry in a jersey pocket, triathlon bag or training shorts. Taking them takes a second but requires you to drink water at the same time for correct absorption. On the bike this is the most logical form of administration: you are already drinking from a bottle anyway. Capsules are also available with added caffeine for the final phase of a long race.

Chewable electrolyte tablets are a more practical alternative in situations where you do not have water immediately available: in a transition zone, on the treadmill or during a running lap in a triathlon. They are quick to take, taste neutral to slightly fruity and work just as fast as capsules. The dosage per tablet is slightly lower than per capsule, so with high sweat loss you take several tablets at once. Choose capsules for use on the bike or during structured training; choose chewable blocks for triathlon races or for use on the go where you have no water at hand.

What to look for when buying?

Magnesium form determines absorption and tolerance

Not all magnesium forms are equal. Magnesium oxide is the cheapest variant but has a low bioavailability of around 4 percent: most of it leaves the body unused via the gut. Magnesium citrate has a bioavailability of 25 to 30 percent and is well tolerated. Magnesium bisglycinate has a comparable or slightly higher absorption and is the best-tolerated form for people with a sensitive digestion. Triple magnesium formulas combine several well-absorbable forms for a broader effect. Avoid products with magnesium oxide if you actually want to make up a deficiency.

Electrolytes: how much and when

The electrolyte requirement during exercise is highly individual and depends on how heavily you sweat, the temperature, the duration of the effort and the sodium concentration of your sweat. A general guideline is 300 to 500 mg of sodium per hour during intensive training above 20 degrees Celsius. Start with the recommended dosage on the packaging and adjust based on how you feel during training. Take electrolyte capsules consistently throughout training, not only once you already have cramps: at that point it is too late to correct the deficiency quickly.

Stacking: what combines well

Omega-3, magnesium, vitamin D3 and probiotics can be combined without problems. Take fat-soluble supplements (omega-3, vitamin D) with a fat-rich meal for better absorption. Take magnesium in the evening separately from calcium if you use both, because calcium and magnesium in high doses can inhibit each other's absorption. Probiotics are preferably taken in the morning on an empty stomach for maximum survival of the bacterial strains in the stomach. Vitamin C in powder form dissolves quickly in water or juice and can be taken at any time of day.

Use during training versus daily use

Daily supplements (magnesium, omega-3, vitamin D, B complex, probiotics) work by cumulatively building up a good status in the body over several weeks. Their effect is not acute: you notice the difference after two to six weeks of consistent use. Electrolytes during training have a direct, acute effect on hydration and muscle function and are only useful if you take them at the right time. Combine daily supplements for the basis with electrolytes for training and racing if you want full support. Also take a look at the energy gels for fuel that you take together with electrolyte capsules during a long training session or race.

Our advice: for most active endurance athletes, magnesium (in citrate or bisglycinate form) is the most impactful investment. Add omega-3 if you eat little oily fish, vitamin D3 from October to April, and electrolyte capsules for training sessions and races longer than 90 minutes. Build up step by step: start with one or two supplements, evaluate after four weeks and then add what your training really lacks.

Who are vitamins and minerals for athletes suitable for?

• Triathletes and endurance athletes who train long and intensively several times a week and therefore have higher requirements for magnesium, electrolytes and recovery-supporting nutrients than is achievable through ordinary food.
• Cyclists and runners who are at risk of electrolyte deficiency and muscle cramps at high temperatures or during long endurance efforts, and who want to keep their performance stable until the end of the training session or race.
• Athletes who train in autumn and winter and get insufficient sun exposure for vitamin D production, or who regularly become ill during intensive training blocks because of a suppressed immune system.
• Endurance athletes with a vegetarian or vegan diet who do not eat oily fish and have to supplement omega-3 via capsules, or who are lactose intolerant and need lactase to use dairy-based recovery shakes without complaints.
• Athletes who want to simplify their supplement intake with a multivitamin as a broad base, supplemented with targeted products such as magnesium or electrolytes based on their specific needs and training pattern.

Need help with your choice?

Do you not know which vitamins or minerals best match your training and diet? Then we are happy to help you further. You can reach our triathlon specialists by phone on +31 (0)413-256800, send an email or visit our triathlon shop in Volkel, the Netherlands.

Frequently asked questions about vitamins and minerals for athletes

Which magnesium form is best for athletes?

For athletes, magnesium citrate and magnesium bisglycinate are the most recommended forms because of their high bioavailability and good digestibility. Magnesium citrate is well absorbable and is available in tablets and powder form. Magnesium bisglycinate is bound in the amino acid form and is the most stomach-friendly choice for athletes with a sensitive digestion. Triple magnesium formulas combine several forms for a broad and staged effect: a fast-acting form for immediate absorption and a slower form for the night. Avoid magnesium oxide, which is relatively cheap but poorly absorbable.

When do I use electrolyte capsules during a triathlon?

Take electrolyte capsules from the start of the bike section in races longer than 90 minutes: not only once you already have cramp, but preventively at set times. A general guideline is one capsule per 30 to 45 minutes at normal temperatures, with greater frequency in warm weather or heavy perspiration. Always take them with water, not with a concentrated energy drink. In the transition zone towards the run section you can switch to chewable electrolyte tablets that are easier to take without stopping for a bottle.

Is a multivitamin for athletes useful if I already take magnesium and omega-3 separately?

A multivitamin for athletes fills a different gap than targeted supplements: it covers vitamins and minerals that you might forget or that are difficult to get through food on busy training days, such as zinc, selenium, vitamin K2 and the various B vitamins. If you already take magnesium and omega-3 separately, choose a multivitamin without these two nutrients or check the dosage to avoid stacking. A multivitamin is not a replacement for a varied diet but a practical safety net for athletes who do not always eat perfectly.

Is omega-3 in fish oil or in plant-based form better?

Omega-3 from fish oil contains EPA and DHA directly, the active forms that the body uses. Plant-based omega-3 (ALA, from flaxseed or chia seed) has to be converted by the body into EPA and DHA, but that conversion is inefficient: only five to ten percent of ALA is actually converted. For vegetarians or vegans, algae oil capsules are a better choice than plant-based ALA sources, because algae oil delivers EPA and DHA directly like fish oil but without animal origin.

Can I take all supplements at once or should I spread them out?

Most daily supplements can be taken at the same time, but spreading them out over the day improves absorption. Take fat-soluble supplements (omega-3, vitamin D3) with a fat-rich meal, preferably in the morning or afternoon. Take magnesium in the evening before going to sleep. Take probiotics in the morning on an empty stomach. Vitamin C and B complex can be taken with any meal. Electrolyte capsules and chewable blocks are intended only for use during training; taking them daily outside training has no added value and gives an unnecessary sodium load.