Did you take your vitamins today? That seems like a simple, straightforward question, but as you probably know, correct supplementation can sometimes feel like an elaborate affair. Not only are there tens of thousands of vitamins, supplements and combination formulas to choose from on the market, once you finalize your regimen, you need to plan out exactly when you’re going to take them for maximum benefit.
For example, if you’re a bodybuilder, you want your amino acid supplements (lysine, taurine, etc.) to work quickly, fueling your endurance and delivering maximum results to complement your hard work in the gym. So, what do you do? How you take your supplements can be just as important as what you take. Not all supplements are absorbed the same way, with some being water-soluble, while others are fat-soluble. If you take your amino acid supplements with a meal, your normal digestion process may slow or even hinder optimal absorption.
But food isn’t the only variable you need to consider when deciding how and when to take your supplements. Let’s clear up some confusion with a few simple rules.
Does Timing Really Affect Vitamin and Supplement Benefits?
When it comes to timing supplements during the day, it’s best to look at the directions and take notice of any supplements that should be taken on an empty stomach or at specific times of the day. It’s important to follow those recommendations unless your doctor or health care provider has stated otherwise.
The main thing to keep in mind is intended benefit. For example, melatonin should be taken at night since it helps support healthy sleep.
Amino acids should usually be taken on an empty stomach for maximum absorption,1 but since amino acids are commonly taken for endurance and recovery surrounding workouts, optimal timing depends on which amino you’re taking and why. For a deeper dive into amino acid benefits and timing, check out Do Workout Supplements Work & When Should I Take Them?
Fat-Soluble and Water-Soluble Supplements: Tips for Max Benefit
When it comes to fat- or water-soluble supplements, your best bet is to follow the directions on the label of each supplement you take and separate the “with food” supplements from the “without food” supplements to avoid confusion. This way you’ll be sure to take each type in a manner that best supports absorption.
Best Time to Take Water-Soluble Vitamins (C, B Vitamins)
In reality, solubility and timing are separate conversations. Water-soluble vitamins can be taken at whatever time of day makes sense with their intended benefit. One thing to keep in mind about water-soluble vitamins is that your body can only absorb so much at one time—any excess will be excreted. Quick tips for water-soluble supplements would include:
- Vitamin C may cause upset stomach if taken with water only. If that is a concern, take with a light meal and plenty of water. Also consider taking smaller doses twice daily as excess intake is not absorbed.
- B vitamins support healthy energy levels, so take them in the morning or early afternoon for best results.
- Magnesium can have a calming effect, so you may take it in the evening to support restful sleep.
If the directions say to take the supplement on an empty stomach, follow those directions carefully and don’t take them with food. Take them at least 30 minutes before a meal or at least two hours after eating.
Best Time to Take Fat-Soluble Vitamins (A, D, E, K)
Fat-soluble vitamins, like A, E, D and K, are better absorbed when taken along with healthy fats or oils.2 So for example, a vitamin D3 & K2 bone health supplement should be taken with a meal—breakfast may be most convenient, but that shouldn’t be considered a hard rule.
While it is helpful to take a fat-soluble nutrient with a meal that contains healthy fats, in general solubility should not impact the time of day you take your vitamin or supplement. Base your timing on the intended benefit.
Timing Based on Your Schedule and Routine
Should I Take Supplements Before or After Exercise?
Whether it’s for weight loss, muscle building or general cardio fitness, there’s a reason you go to the gym. If you take supplements specifically designed to support those efforts, it’s important to know what to take and when.
After all, why wouldn’t you want to maximize your endurance, strength and fat burning during your workout?
For energy supplements like caffeine or green tea, try to take those about an hour before you begin exercise. Whey protein powders, shakes and other supplements that provide fuel for your muscles, like creatine and BCAAs, can be taken about 15 minutes before exercise.
After workouts, you may want to fuel those muscles once again. Whey protein is great both before and after workouts. You could also consider adding a protein that digests more slowly to optimize post-workout recovery. Other supplements that support recovery include beet root complex and amino acids.
Can I Take All My Supplements Together?
Some supplements may have unintended interactions with other nutrients. As an example, you may want to avoid taking botanicals high in tannins, such as cinnamon or clove, with iron supplements, as they can inhibit iron absorption.3 In those cases, you will need to space things out. And it isn’t just supplement-to-supplement interactions you’ll need to consider. Some supplements also interact with prescription medicines. An example would be the optimal timing for taking probiotics if you’ve also been prescribed a round of antibiotics. In such a case, it’s always best to discuss with your doctor.
You’ve decided to take more control over your health by supplementing your nutrition, and that’s a great first step! Now you need to educate yourself about how those supplements work so you can get the most out of your nutritional regimen, get the timing right and make sure you’re taking them in the safest way possible to limit any potential side effects or interactions.
Remember these timing “rules of thumb” for best results:
- Consistency matters most —pick a time you’ll remember every day
- Excess amounts of water-soluble vitamins will be excreted rather than used so it may be best to split your intake into multiple doses throughout the day
- Take fat-soluble vitamins with the largest meal of the day
- Pair the benefits of the supplement with the time you take it (energy in the morning, relaxation in the evening)
The rules for when to take most supplements are not hard and fast. It depends on what you take, how much you take and why you take it. Experts say your best bet is to carefully read and follow the directions on the supplement labels and do your own research on the specific nutrients. As always, consult with your doctor before adding a new supplement to your regimen to make sure you enjoy the most benefits.
With this information on hand and the guidance of a health care provider, you’re sure to find not only the most beneficial supplements to meet your needs but also have the tools to craft a time and routine that supports your health goals.
About Lindsey Toth, MS, RD
Lindsey is a nationally recognized registered dietitian and nutritionist with a soft spot for ice cream. She empowers people to take charge of their health by finding the balance between the pleasure and nourishment in food. Her philosophy is that you should take care of your body because it’s the only permanent home you have. It’s what inspired her to pursue a career in nutrition.
*These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease.
Sources
- Cooperman, T. Must I Take Amino Acid Supplements on an Empty Stomach? August 2017. ConsumerLab. Read source
- Cooperman, T. Which Supplements Should be Taken with Food? July, 2021. ConsumerLab. Read source
- Cosme, F., et al. Molecules. 2025 Feb 9;30(4):800. Read source
