Vitamins, minerals and water

Start of a race; photo by David Knight

Start of a race

Vitamins and minerals are not a source of energy, but they are needed by the body to maintain your health. Inadequate vitamins or minerals can certainly have a harmful impact on your running performance. However, if you eat a balanced diet of largely unprocessed foods, it is likely that you are getting enough of the key vitamins and minerals.

In judging your vitamin and mineral intake you should take the following into account:

  • if you are eating packaged or processed foods, they may have fewer vitamins and minerals than fresh food;
  • intensive food production (e.g. farming, storage and transportation) means that some foods don’t have as many minerals and vitamins as their less intensively‑produced counterparts;
  • if you sweat a lot (e.g. because you are running in a hot climate) you may lose essential minerals in your sweat which need to be replaced;
  • regular exercise increases your vitamin and mineral requirements compared with sedentary people, because they are needed for metabolism, maintenance of tissue and manufacture of red blood cells; the recommended daily allowances (“RDAs”) that are published by the Government are a guide for the general population, and you may well need to consume more than these guidelines;
  • high intensity training may weaken your immune system, and increased intakes of vitamin C will help to boost your natural defences;
  • it is possible to take too much of some vitamins and minerals (particularly vitamins that are not water soluble, such Vitamins A, B6 and D); large excesses of these can lead to nutritional imbalance and, in extreme cases, serious illness.

On the whole, you should aim to get your vitamin and mineral intake from your diet. However, many active people choose to supplement their diet by taking a multi-vitamin supplement.  This provides insurance, in case the vitamins are lacking from the food you eat.  But you should not take doses of vitamins or minerals significantly above the recommended daily allowance without first seeking medical advice, and certainly not of vitamins that are not water soluble.


Water is by far the most important nutrient in the runners’ diet. Yet for some reason, it is often neglected in books and articles about running.

You should probably drink more water than you do right now. This is for two reasons. First, most people – even if they don’t do any exercise – don’t drink enough water. Second, as a runner you need more water because you lose water through sweat.

Water is important because it helps to regulate your body temperature (through sweating), and it makes up 82% of blood and determines its viscosity.   Water is also stored with glycogen in your muscles, so if you don’t drink enough water your body will not be able to store energy.  High water intake will also help your body to regulate toxins, and keep your skin healthy.  As we shall see in Chapter 7, dehydration can lead to poor performance; but excessive hydration is also dangerous.

Drinking water

As a very approximate rule of thumb, you need about 1 litre of water for every 1000 kcal you consume during the day (this is your base water intake; you need extra when you are exercising).  You also need more in hot or humid weather.  This means that if you have a daily calorie intake of 3000 kcal, you need to drink about 3 litres of water each day.  That is a lot, and may well be more than you are drinking at the moment.

Try to get into the habit of drinking a pint of water when you first get out of bed; and then sip water throughout the day.  Many healthy people keep a sports water bottle next to them at work, so that they can sip frequently.

The following drinks are diuretics – that is, they make you urinate and so increase the amount of water you need:

  • coffee and tea
  • caffeinated drinks such as cola
  • alcoholic drinks

If you drink any of these, you should aim to increase your water intake by at least the volume of the diuretic drink.  (So if you have a 350ml can of cola, try to drink 350ml extra of water as well.)

The urine colour test

It is fairly straightforward to check if you are drinking enough, by looking at the colour of your urine.  If your urine is clear, then you are well hydrated.  If it is yellow, or dark, then you are dehydrated and need to drink more. (The University of Connecticut has developed a guide, like a paint colour chart, to enable you to judge your hydration.) Note that your urine may be discoloured by some vitamins and minerals – for example, Vitamin B6 tends to make your urine fluorescent yellow – so that if you take vitamin supplements you may not be able to judge your hydration so easily by looking at the colour.

Rapid weight loss is also a good indicator of dehydration. If you weigh yourself after a workout and find you have lost a lot of weight, then you should not congratulate yourself, but go to the kitchen and get yourself a pint of water or a sports drink.

9 Responses to Vitamins, minerals and water

  • rachel:

    Hi, the advice on water intake is a bit out of date. taking 3 litres of ‘extra’ water a day for a 3000 calorie intake is not sensible advice, most water can be obtained from the foods and drinks you are ingesting so doesn’t need to be supplemented. also, water is a diuretic as well as coke, coffee and tea. there is no evidence that tea, coffee and soft drinks cause you to pee more often than drinking water. monitoring your thirst is relevant and pee colour is relevant. it’s not important to drink before you get thirsty either.
    nobody has died during a marathon from dehydration but they have died from hyponatraemia caused by drinking too much water.
    it would be great if the advice on water was updated.

  • Alex:

    I usually would never comment in a situation like this, however, I would hate for others to read your comment and distrust the good advice given in this article as your comment is quite misinformed.

    There is in fact extensive scientific and clinical evidence to show that caffeine and alcohol are diuretics and therefore “make you pee more” than when drinking non-diuretic liquids like water. And as for no one dying from dehydration, one of the most common causes of morbidity in marathons is renal failure which is precipitated by dehydration. It is true that you can become hyponatraemic from drinking too much water, however, this risk is easily combated by using electrolyte replacement therapy such as sports drinks as these contain sodium.

    Please review your research before posting misleading comments on a site which people come to for advice.

  • Bill:

    I enjoyed the article and I rarely post comments on pages but I felt it necessary to include personal insight.

    @ Rachel

    Where did you come by your information? Caffeine is a stimulant which increases your metabolism and therefore increases the rate at which your body processes fluids which leads to increased urination. I’m not sure who told you that nobody has died from dehydration during a marathon but that is wildly inaccurate. I had a personal experience where I nearly died from dehydration during a training run (led to hospitalization). Finally, if your body feels “thirsty” you are already experiencing dehydration. This doesn’t mean that you can’t continue to race but your body is telling you in a round about way that you need to increase your water consumption/fluid intake.

    I did not mean to pile on to Rachel’s comments, but I do agree with Alex. That kind of advice could prove fatal for an uninformed and aspiring runner. If you have scientific evidence to support your claims then please cite your sources. Perhaps your post was dripping with sarcasm and maybe I just missed it.

  • Lynn:

    Anti diuretic hormone is blocked by caffeine and alcohol. Therefore they are diuretics. Water is not a diuretic. So again Rachel was wrong. There are also extensive studies which show that hunger in the body is often confused with thirst…which discredits the whole don’t drink before you’re thirsty idea.

  • Tomas:

    So many opinions. So many claims about what studies have shown. And yet, not a single reference to any specific peer-reviewed study.

  • Dj:

    This is exactly what they mean when they say “Listen to your body”. Nothing has been proven as absolute truth in running science. And it’s upto people not to believe everything they read or everything they are told to do. There are too many studies. From three years of my experience as a noob runner I’ll go with Alex and Bill here. This article will be of good help for most of the noobs.

  • Samantha:

    This is a peer-reviewed article published in Nutrition Reviews. I don’t know if you feel like reading the full length of it, but the tables are definitely worth looking at. Table 5 shows recommended fluid intake for each range of estimated caloric intake. All ratios are greater than 1.0 past the age of 3 years. This means that the 3000kcal – 3L recommendation is quite acceptable. While some water we do get from food, that should be enough to bump up the values to a more acceptable relationship. Also, the recommendation was NOT to drink 3L at one time, which would certainly cause issues, but to sip it throughout the day, starting with a pint (under 500mL) in the morning to replace fluid lost through sweat and respiration, etc, throughout the night.

    According to Dr. Jake Emmett, a Ph.D. in Exercise Science, hyponatremia during marathons was found at higher rates in those with longer times, as they spent more time on the course and therefore more time drinking water. The highest risk was for those who spent 4+ hours running.It was also higher in those who took NSAIDs (a noteworthy warning) as those may cause water retention. However, hyponatremia occured in less than 0.3% of participants (SOURCE: Hew, T.D., J.N. Chorley, J.C. Cianca, and J.G. Divine. 2003. The incidence, risk factors, and clinical manifestations of hyponatremia in marathon runners. Clinical Journal of Sport Medicine 13:41-47.)

    This being said, most people “Running for Fitness” will NOT be running 4+ hours. If they do, hopefully they will take the time to research proper hydration methods pre- during and post-exercise.

    Additionally, according to the American Chemistry Society, it takes about 6L of excess water (above normal hydration levels) to kill a 165lb person. The 3L recommended here will come nowhere close to that.

    I agree with Alex and Ben, and the research I did on the issue certainly supports their POV.


    II had recently hyponatremia incident, it means critically low sodium, but not just after marathon, half marathon, or any long run distance at all, but only after 3 minutes of running in the park at morning n being after salty drink- 300ml… I never drink much water, but less than 1 liter of all types of drinks during day. I don’t feel thirst n don’t like drinking, just forcing myself to drink at all. I have thirst disorder called adipsia, insufficient or lack of thirst / the other pole of polydipsia-intensive thirst, typical for diabetes mellitus/. Doctors don’t recognise that, however. Having such incident a week ago: breath difficulty, fatigue n nausea I went to A& E n it occurred I had critically low sodium which could end with sudden death. The problem is, my sodium is running out with urine / my urine is often salty/, so it’s real reason, n not overhydration! That ‘s not all what I can say here as that matter is much more complicated, but generally I’d rather agree with Rachel opinion.

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