When to take supplements?

This question is about Nutrition

Elle Penner, MPH, RD

The best time to take supplements varies from supplement to supplement. For many supplements, the best time to take them is whenever you’re most likely to remember, as the time of day does not appear to enhance or reduce their effectiveness. 

However, other supplements, like

caffeine for sports performance

or melatonin for sleep, are more time-sensitive. Taking caffeine 15-60 minutes before exercise appears most beneficial for performance. Similarly, melatonin should be taken 30-60 minutes before bedtime as it takes about 30 minutes to start working and melatonin levels to rise. 

When it comes to vitamins and minerals, knowing how to take the supplement matters more than when you take them. Here are a few things to consider regarding vitamin and mineral supplements and timing:

  • Water-soluble vitamins: Vitamin C and the B-vitamins are water-soluble and easily absorbed, therefore they can be taken with or without food at any time of day. Because the B vitamins play important roles in metabolism and energy production, some suggest there may be an upside to taking these in the morning. Additionally, research suggests that vitamin B6 may have the potential to disrupt sleep and promote vivid dreams so taking this particular supplement earlier in the day may be preferred [



  • Fat-soluble vitamins A, D, E, and K: These vitamins can be taken at any time of day and are best absorbed when accompanied by a meal or snack containing dietary fat.

  • Multivitamins: Multivitamins can be taken at any time of day. Because they contain both fat- and water-soluble vitamins and can cause mild stomach upset, it’s generally recommended to take them with a meal.

  • Iron: Iron supplements are best absorbed when taken on an empty stomach. Because of this, many people find it best to take supplemental iron first thing in the morning before having breakfast. To improve absorption, pair iron with 200 mg of vitamin C or an 8-ounce glass of orange juice. 

Your body is unique, and your nutrition should be, too. Learn more about how

Elo Health

uses Smart Nutrition to recommend the right nutrition and supplements for you. 

Supplements on a spoon with produce in the background


  1. Aspy, D. J., Madden, N. A., & Delfabbro, P. (2018). Effects of Vitamin B6 (Pyridoxine) and a B Complex Preparation on Dreaming and Sleep. Perceptual and motor skills, 125(3), 451–462.