Have you wondered when to take dietary supplements? I know I have. I decided to do some research on the best time of day take supplements to get the most benefits and also improve sleep. Or at least not interfere with getting to sleep at night.

Some pump you up and give energy, some make you sleepy. I wanted to fine-tune all my supplements and maybe you do too.

Typically I’ve always taken them after my morning meal. But since I’m not on a multivitamin, I want to get the most benefit from each individual supplement. Sachin Patel of Living Proof Institute (n.d.), Kathryn Watson of Healthline (2018), and Institute for Natural Healing (2017) give some great information about the best time to take various supplements.

Let’s get into it.

Fat-Soluble Vitamins – A, D, E, K

Fat-soluble vitamins are best absorbed with fat so taking your A, D, E, or K with lunch or dinner (or right after) gives you the best absorption. Keep in mind that any extra is stored in the liver and you can get too much and risk toxicity. I worry more about this with vitamins A and E. I only take E with tocotrienols at most every other day.

When to Take Dietary SupplementsYou don’t want to take hyper doses of Vitamins A and E, especially. Just the recommended amounts is fine.

Take any of these with a meal.

Vitamin D should be taken early in the day (with breakfast or with coffee MCT oil) as there is evidence it might interfere with restful sleep (Asprey, 2020). However, being low on Vitamin D can cause insomnia and poor sleep. So take it in the morning or with lunch.

The upper limit of Vitamin D3 is about 50,000 IU. That’s a lot. A doctor I follow, Dr Sherry Rogers, recommends taking 10,000 IU of Vitamin D3 5 days a week, taking the weekends off.

Side note: We get very little Vitamin D3 in the diet, mainly from the sun, so supplementing Vitamin D is extremely important if you don’t live near the equator. 

Related Article: Side Effects of Low Vitamin D

Water-Soluble Vitamins – The B’s and C

The all-important B-Complex vitamins and Vitamin C are best absorbed on an empty stomach. So first thing in the morning or 30 minutes before eating (Watson, 2018). This was an eye-opener for me.

Since they are water-soluble, they aren’t stored in the body so you generally won’t overdo it. A good B-complex and C supplement should do it. I take 1000mg of Vitamin C per day

B-ComplexB-vitamins can increase your energy levels so you don’t want to take them late in the day, or you could have trouble falling asleep.

Related Article: What is B Complex Good For?

Essential Fats – Omegas, MCT

According to Patel (n.d.), fats like Omega 3’s and MCT (medium-chain triglycerides) oil should be taken in between meals, on an empty stomach. If they bother you on an empty stomach, then eat something low fat with them.

Amino Acids

When to Take Dietary SupplementsAmino acids like taurine should be taken on an empty stomach. I like to dissolve some taurine powder in water before I head to the shower in the morning. Giving about 30 minutes before you eat will allow you to absorb the amino acids. And they bind to proteins so that’s the main reason to have an empty stomach when you take amino acids.

Related Article: Taurine and the Brain


In general, magnesium should be taken at night, as it can make you sleepy. It really helps with sleep too. Other minerals can have a calming effect as well, so what better time to take them than before you go to bed. If you need two doses a day, take as directed but if you can take one in the afternoon and then evening, it might help you sleep a little better and stay awake during the day.