Vitamins Before or After a Workout? (According to Science)

Vitamin A

Vitamin C

Among ensuring 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) [1].
• Relieving exercise-induced respiratory symptoms (proven in athletes who took vitamin C pre-workout) [2].
• 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

B vitamins are key to a healthy metabolism, powering your cells to tap into food's energy. This helps sustain energy during high-intensity workouts, weight training, or similar activities.

Vitamins like B6, B1, B12 help your body use and store energy from protein and carbs, make hemoglobin and red blood cells, and maintain a healthy nervous system. B-complex also plays a role in metabolizing amino acids and proteins, crucial for muscle repair.

Taking a B-complex supplement is great for overall health and fitness performance. Since your body doesn't store these vitamins, it's best to take them daily in the morning.

Vitamin B12, often in animal products, absorbs better with food. And since vitamin C can hinder B12 absorption, space them out by at least two hours.

Vitamin C and E

Exercising boosts insulin sensitivity, helping your body absorb nutrients better and use them to build muscle rather than store fat [7] [8]. However, high-dose antioxidant supplements might reduce exercise-induced oxidative stress in those deficient, but they're not always effective in well-trained athletes.

In fact, the National Library of Medicine says that too much post-workout vitamin E and C supplementation might decrease insulin sensitivity and negate some benefits of exercise [9] [10]. (Eating antioxidant-rich foods right after training could cause the same issue.)

In one study, 40 young, fit men exercised five days a week for four weeks, including running and cycling. They also took 1000 mg of vitamin C and 400 IU of vitamin E daily.

This high antioxidant intake actually wiped out the exercise's positive effects on insulin sensitivity.

Antioxidant Supplements

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 [11].

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.