When is the Best Time to Take Supplements?

When is the Best Time to Take Supplements?

One of the questions that nutritionists and dieticians get asked the most is: “what is the best time to take supplements?” This is perfectly understandable, as you want to ensure that you are receiving as much of the goodness as possible. Unfortunately, like many questions in this field, the answer isn’t straightforward, as there are a number of factors that are at play. In this article, we are going to uncover the nuances and hopefully help you get the most out of your supplements.

What Time of the Day Should I Take Supplements?

Generally speaking, the time of day you take your supplement isn’t going to make or break your nutrition. Sure, there are certain supplements you would be much better off taking earlier in the day such as caffeine or ginseng.  Others, such as magnesium, may be better taken later in the day (because it can help you sleep). For the vast majority of supplements there are no significant advantages or disadvantages to the time you take them. Like nutrition in general, it’s based on your personal preferences and doing what suits you best.

Supplement timing is far more important when the overriding aim is to boost sports performance. Athletes not only need to perform well at the specific time of their event, but also need to adapt and recover – something that bespoke nutritional strategies can help to facilitate. If you wish to find out more about sports nutrition supplements you can follow the links to the articles we have written about improving exercise performance and recovery.

With a Meal or on an Empty Stomach?

The type of supplement you are taking will influence whether or not it is best consumed with a meal. Nutrients can be split into two groups: water-soluble or fat-soluble. Water-soluble nutrients can be taken with a meal or on an empty stomach and their absorption does not differ significantly. As the name suggests, fat-soluble nutrients are much better absorbed when taken alongside a meal containing a good fat source.

Water-soluble vitamins (B vitamins and vitamin C) need to be consumed daily as we do not have the ability to store these, apart from a small amount of vitamin B12. Because they cannot be stored, there is little risk of them building up to a toxic level and many people take high doses of water-soluble vitamins. For example, high doses of niacin (vitamin B3) are often taken for cholesterol control.

Although water-soluble vitamins can be taken at any time, there are certain supplements that are best taken without food, in order to support their function. Probiotics, digestive enzymes, apple cider vinegar, green tea and glucomannan are examples of such supplements.  

Opposite to B vitamins and vitamin C, the fat-soluble vitamins (A, D, E & K) do not need to be consumed daily, as they are stored in fat cells to be used as required. Because of this, an advantage of fat-soluble vitamins is that you can take a weekly or even monthly dose at one time rather having to take them daily. This is ideal for those who often forget to take their supplements.

Aside from vitamins, there are other popular supplements that are indeed fat-soluble: Co-Enzyme Q10, CBD, lutein, curcuminoids (from turmeric) and gingerols (from ginger) are all examples of ingredients that you are best off taking with a meal.

Another reason why people are often best to take a supplement with a meal is to avoid an upset stomach. Common supplements that can cause gastrointestinal distress are minerals such as iron and zinc, fish oils and garlic (whether you have a problem with such supplements is highly individualised).

For the majority of supplements, it is likely best practice to take with a meal to help absorption and minimise the chance of suffering digestive issues. However if you are unsure it’s always best to seek advice from a nutritionist, dietician or a pharmacist.

Supplements that Work Well Together

As you may be aware, there are certain nutrients that work synergistically within the body to help nutrient absorption and utilisation.

Iron & Vitamin C

One of the best known synergistic pairings is vitamin C and iron. Although heme iron (from meat, fish and dairy) is readily absorbed by the body, non-heme iron (from plant-based sources) is not so much. Scientists have known for years that vitamin C has the ability to markedly boost the absorption of non-heme iron.

Without getting too technical, when vitamin C and iron are consumed together, they have the ability to bond to one another. This bonding helps to increase the solubility of iron in the small intestine, subsequently boosting absorption. Studies have shown that combining the two can boost bioavailability four-fold.

So if you are taking an iron supplement or actively trying to boost your iron stores through non-animal based foods, it would be in your best interest to take it alongside a vitamin C supplement or foods such as citrus fruits, leafy greens or peppers.

Calcium & Vitamin D

Another classic pairing is calcium and vitamin D. We all appreciate calcium’s importance in strong bones and teeth, but its roles in neurotransmission, muscle function and digestive function are lesser-known. While vitamin D is known to support a healthy immune system and psychological function, its primary role in the body is the absorption of calcium (and phosphorus). Vitamin D works by activating receptors in the small intestine that allow calcium to permeate into the blood stream.

Although we can make ample vitamin D in the UK through sunlight from April to September, the rest of the year it can be a challenge to obtain a sufficient amount. This claim is substantiated by the latest National Diet & Nutrition Survey which has shown that 29% of adults and 37% of children aged 11-18 were deficient in vitamin D between January and March.

As vitamin D is difficult to get through food alone, you can see why the Department of Health recommend that everyone supplements with vitamin D during the colder, darker months. ‘At risk’ populations such as older adults, those with dark skin and those who spend little time outdoors are recommended to supplement year-round. Heeding this advice will hopefully make conditions such as osteoporosis (weak, brittle bones) much less common.

The Interaction of Minerals

Many dietary minerals compete with each other for absorption, meaning that an excess of one can deplete supplies of another. This is generally a problem that arises through supplementation, where high doses of minerals are often consumed.

Most of us would agree that a healthy diet can provide all the nutrients we need if structured correctly. Sadly, research into our diets shows that many of us are falling well short of the recommended mineral intake, meaning supplementation definitely has its merits. So for those who would like to, or need to take mineral supplements, it’s good to know how to use them to your advantage.

Iron, Zinc & Copper

One of the most well researched minerals interactions involves zinc and iron. High levels of zinc don’t just affect iron, however, but can also deplete the body of copper. This is a vicious circle, as copper is needed to assimilate iron into haemoglobin. This means that low copper levels will make the iron you have less effective.

Zinc is so effective at depleting the body of copper that is has become one of the most-used treatments for Wilson’s disease – a rare genetic condition where copper accumulates in the liver, brain and eyes.

Therefore, if you are planning to take a zinc supplement, it would be best to take it at a different time to sources of iron. If you are supplementing with zinc, it would also be a good idea to ensure you are including copper-rich foods in your diet (seafood, nuts, legumes, dark chocolate) or a supplement.

Sodium, Calcium & Magnesium

Calcium and magnesium are two of the most common nutrients to take in supplement form, given their importance in bone health, muscle function and metabolism to name a few examples. However, a typical western diet, which is high in salt, may be mean that these two minerals struggle to reach the areas of the body where they are most needed.

When the body has elevated sodium levels, it attempts to get rid of it through urine. However, research has shown that this process actually depletes calcium and magnesium as well as sodium. Researchers stumbled across these findings as they were looking to explain why those with a diet very high in salt are more likely to suffer from osteoporosis and kidney stones.

A low sodium diet is typically recommended for heart, kidney and eye health, as sodium increases blood pressure. However, experts have realised that it can also affect health in many more ways now this information has come to light. The easiest ways to cut sodium intake are to consume less processed food and to be mindful of how much salt you are adding to food and recipes.

Foods/Drinks That Inhibit Nutrient Absorption

When it comes to certain minerals, it’s not just each other they need to worry about. There are certain compounds within some plants, often known as ‘anti-nutrients’, which inhibit absorption.  Some of the most common are:

  • Glucosinolates – Found in cruciferous vegetables (broccoli, cabbage, sprouts and cauliflower), these compounds affect the absorption of iodine. Iodine is a trace mineral found in seafood and dairy, which is primarily needed for thyroid function. It also has a role in cognitive function, skin health and the nervous system.
  • Phytates, Lectins & Saponins – These compounds, which are found in whole grains, nuts and legumes, interfere with the absorption of a number of essential minerals including calcium, magnesium, iron, zinc and phosphorus. It is however possible to significantly decrease the presence of these anti-nutrients by soaking the food in water overnight.
  • Tannins – These polyphenols are found in tea, coffee and red wine and are known to possess a powerful antioxidant capacity. However, these compounds can markedly reduce the absorption of non-heme iron, so it definitely wouldn’t be advised to take an iron supplement with your morning brew.
  • Oxalates – Oxalates can be found in particularly high amounts in spinach, bran flakes, almonds, beetroot and rhubarb. Oxalates bind to calcium and prevent it from being absorbed, so make sure you don’t take your calcium supplement with a meal that contains the above foods. Oxalates can be decreased through soaking however, and as they are heat sensitive cooking lowers their effect.


Hopefully this article has furthered your knowledge of nutrition and helped you to understand how to fully benefit from the supplements you take. From reading this article, I am sure you now appreciate all of the factors that are at play and can now use these to your benefit. As we have covered quite a few different aspects, it seems appropriate to list some of the key take home messages:

  • The time of day you take a supplement is not of much importance. However this does become a key factor when taking supplements for sports performance.
  • Water soluble nutrients such a B vitamins and vitamin C can be taken with food or on an empty stomach. Fat soluble nutrients should be taken with a meal containing fat for optimal absorption. 
  • It is recommended that you take your supplement with a meal if it causes you to have an upset stomach.
  • Non-heme iron, the type found in supplements and plant-based foods, should be taken with a source of vitamin C to boost absorption. Anti-nutrients found in hot beverages and certain grains, nuts and legumes can decrease iron bioavailability.
  • To ensure optimal calcium absorption, a diet high in vitamin D and low in sodium is required. Ideally, sources of calcium shouldn’t be taken alongside foods high in oxalates.
  • Anti-nutrients can be reduced through methods such as soaking and cooking but not fully eliminated.