If you exercise regularly as many of my clients, taking a multivitamin supplement may be highly beneficial for building muscle, producing collagen, enhancing cell membrane repair, providing structural strength, reducing stress, losing weight, and supporting other fitness goals you may want to achieve.
However, with lots of multivitamins marketed nowadays, it’s hard to determine what’ll work for you and how to hit the perfect timing, quantities, and combos for maximized gains.
So, our experts have explored and summed up the key benefits and risks of the essential vitamins for athletes and answered one of the trickiest questions: when to take them - before or after working out.
Is It Best to Take Vitamins Before or After Working Out?
Some vitamins are best to take before, while others after working out to maximize their effectiveness.
It depends on various factors, including:
- The type of vitamins you’re taking (fat-soluble are better taken with an evening meal, whereas water-soluble get better absorbed on an empty stomach, i.e., best taken first thing in the morning before breakfast)
- Their role and the way they may affect exercise (e.g., supporting muscle growth, enhancing post-workout recovery)
- The time when you work out (morning, evening)
- Whether particular vitamin combos are effective or cause an upset stomach and other side effects
- Whether you take any other prescription medications (as even small amounts of particular vitamin supplements can cut their strength), etc.
Reasons to Take a Multivitamin
Even if your diet is nutrient-rich, most experts advise fueling up your strenuous fitness routine with vitamin supplementation.
Taking multivitamins can ensure you get all the necessary nutrients to:
- Avoid any energy-sucking vitamin deficiencies
- Gain enough energy for intense daily training sessions to achieve your gym goals
- Speed up your post-workout recovery
- Help build and maintain muscle tissue
- Protect your tissues
- Prevent bone density loss, osteoporosis, and other diseases
The Roles of Several Essential Vitamins
This substance is essential for protein synthesis, testosterone production in males, supporting bone health, muscle growth, and strength, among many other health benefits.
This fat-soluble antioxidant may help prevent muscle breakdown during long, intense endurance exercises that require maintaining a high level of effort for longer (e.g., jogging, swimming, walking, long-distance running, and similar).
Among ensuring a healthy immunity, preventing infections, and a range of other benefits, science claims that this vital vitamin aids in:
- Lowering cortisol levels and preventing muscle damage caused by oxidative stress (proven in individuals who ate five servings of fruits and vegetables rich in this vitamin every day); 
- Relieving exercise-induced respiratory symptoms (proven in athletes who took vitamin C pre-workout); 
- Collagen production (a structural protein key to strong and healthy muscles, tendons, bones, and skin that enables your joints to handle heavier weights while avoiding injury);
- Metabolizing carbohydrates for fuel to prevent fatigue;
- Formation of anabolic hormones.
You may safely take small doses of vitamin C every day at any time.
Vitamin B Complex
“B complex vitamins are mostly important in metabolism and also in energy processing and recovery. In general, they may help with energy levels. This, in turn helps with maximized results.”
- Dr. David Greuner
The Bs are essential for a healthy metabolism and fueling your cells so that you can use the stored energy from food to sustain high-intensity working out, weight training, or any other similar activity without getting exhausted.
For example, Vitamin B6, B1, B12, and others help the body use and store energy from protein and carbs, use folate, produce hemoglobin that carries oxygen around the body, make red blood cells, and keep the nervous system healthy.
B-complex also aids in metabolizing amino acids and protein critical for muscle repair.
These pre-workout energy boosters should be taken every morning because your body doesn’t store them.
Vitamin B12 (commonly found in animal products) gets better absorbed with a meal.
Also, vitamin C can block B12 absorption, so make sure you take them at least two hours apart.
Vitamin D is crucial for maintaining normal muscle mass, function, and strength , as well as bone protection so that you can withstand strenuous gym sessions, marathon running, and similar activities without inflammation, pain, bone fractures, and similar injuries. 
It enhances the absorption of Calcium (important for muscle contractions and bone strength) and Phosphorus (essential for the synthesis of ATP - usable energy form).
This is another fat-soluble vitamin you can get enough of through a balanced diet.
It’s critical for repairing and building strong membranes of muscle cells that often tear during exercise, fighting oxidative stress and infections, keeping hormonal balance, healthy eyes, skin, and much more.
Although it has powerful antioxidative effects, many studies claim it can cause some adverse effects in athletes if taken before exercise. (Detailed explanation follows.)
Vitamins to Avoid Before and After Workouts
Vitamin C and E
Exercising helps increase your insulin sensitivity and reduce insulin resistance. When your insulin sensitivity is good, your body better absorbs micronutrients and macronutrients, using them to build muscle instead of storing body fat.  
Although antioxidant supplementation in high doses can minimize exercise-induced oxidative stress damage in deficient individuals, it’s not proven to work in well-trained athletes.
(Eating foods rich in antioxidants around or shortly after training may cause the same problem.)
For instance, a group of 40 young, healthy pre-trained men who participated in one study exercised for four weeks, five days per week (warm-up, running, cycling, circuit training, cool-down exercises).
Plus, the participants took 1000 mg/day of vitamin C (ascorbic acid) and 400 IU/day of E vitamin.
Such high antioxidant intake eliminated the beneficial effects of exercise on insulin sensitivity.
Based on research evidence, a hefty dose of powerful antioxidants other than the two well-known above produces the same results - prevent the post-exercise damage caused by free radicals (reactive oxygen species) and decrease insulin sensitivity. 
That’s why my advice is to avoid excessive antioxidant intake (especially if you’re at high risk of diabetes), or if you’re deficient, at least take it one hour after training.
So, Should You Take Vitamins Before or After a Workout?
Since there are pros and cons to taking vitamins both before and after working out, it’s hard to give a universal recommendation that’ll work for all people.
Unfortunately, there’s no magic pill.
So, after reading the information above, you’d hopefully be able to weigh all your options and determine for yourself what vitamins could help boost your gym gains.
Since each person has unique dietary needs, I’d encourage you to consult your doctor or dietitian to get a personalized formula based on your age, sex, health, gym goals, and other relevant factors.
Don’t forget to share your experience and tips with us.