Is Vitamin Water Good for You? What the Research Says About Sugar, Vitamins and Hydration

Key Takeaways

Sweetened vitamin water is a sugar-sweetened beverage. Sugar-sweetened beverages have been linked to weight gain in trials and to higher rates of type 2 diabetes and mortality in large cohorts.[7][8][9]
The added vitamins add little for well-nourished people. In adults without known deficiencies, vitamin and mineral supplementation was associated with little or no benefit in preventing cancer, cardiovascular disease and death.[2]
It does not cover all vitamin needs. In a Canadian analysis, the vitamins most commonly added were B6, B12, C and niacin;[1] fat-soluble vitamin D was not among them.
A real deficiency needs targeted treatment. Deficiencies such as folate or vitamin B12 usually have an underlying cause that needs to be investigated and treated specifically, not with a fortified drink.
Regular vitamin C did not prevent colds in the general population. It shortened colds slightly in adults, and people exposed to brief periods of severe physical exercise may be an exception.[4]
Plain water is a reasonable everyday choice. In a resting study, most of the common drinks tested produced a similar urine output to water.[10]
In my clinical experience, vitamin water is more often an impulse purchase than a real source of needed vitamins. In my view, an occasional bottle matters little, while long-term daily use of the sweetened versions is more likely to harm than help.

Introduction: Is Vitamin Water Good for You?

Vitamin water sits in the cooler right next to plain water, and its labels talk about energy, focus and defence. The name suggests water plus a dose of nutrition. So is vitamin water good for you? The research on what those added nutrients do for a healthy person, and on what the added sugar in the sweetened versions does over time, tells a less flattering story.

When Canadian researchers analysed 46 novel beverages sold in supermarkets, a group that included vitamin waters, energy drinks and novel juices, almost every product provided at least one nutrient in excess of requirements. Yet the authors concluded there was little evidence that consumers stood to benefit from the micronutrients most commonly added to these drinks.[1]

As a physician and a former world champion in Taekwon-Do, I look at drinks like this from two angles: what they do to long-term health, and whether they have any real role in training. This article covers what is actually in vitamin water, what the evidence says about the added vitamins and the added sugar, how it compares with plain water for hydration, and what athletes should keep in mind.

What Is Actually in Vitamin Water?

Vitamin water is flavoured water with added vitamins and, in the regular versions, added sugar. Some brands also sell zero-sugar versions. Formulas vary by country and by flavour, so the nutrition label is the only reliable guide to what a particular bottle contains.

The Canadian analysis gives a good picture of the category as a whole. The median number of added nutrients per product was 4.5, and vitamins B6, B12, C and niacin were the ones added most often.[1] Most products contained three or more nutrients at levels above requirements.[1] With the exception of vitamin C, the researchers found no discernible prevalence of inadequacy for these nutrients among young Canadian adults.[1] Put simply, the vitamins most often added are mostly ones that young adults in that population were already getting enough of.

The same study also examined the packaging. Labels promoted performance and emotional benefits tied to the nutrient formulas, benefits the authors described as going beyond conventional nutritional science.[1]

Patients often ask me whether vitamin waters are worth drinking. The appeal is easy to understand: many people assume they have vitamin deficiencies that a fortified drink could correct, which makes it a clever marketing angle. In my clinical practice, however, I rarely see deficiencies of the water-soluble vitamins these drinks contain, such as the B vitamins, in otherwise well-nourished patients, although they can of course occur. If a patient did have a genuine deficiency, I would not see vitamin water as an ideal way to treat it. In my view, taking the vitamin as a tablet is usually simpler and cheaper.

Vitamin water also does not cover a person’s overall vitamin needs. In my experience, these drinks generally do not contain fat-soluble vitamins at all. From a clinical perspective, fat-soluble vitamins come with their own considerations: they can accumulate in the body, which brings a risk of overdosing. In practice this means that the deficiency I see most consistently in Finnish patients, vitamin D, which is fat-soluble by definition, is generally not covered by these drinks.

The Vitamin Question: Do Added Vitamins Help Healthy People?

The core promise of vitamin water is that extra vitamins improve health. The most relevant evidence on that question comes from supplement trials rather than from studies of vitamin water itself.

An updated evidence report for the US Preventive Services Task Force reviewed 84 studies (N=739,803) of vitamin and mineral supplementation in adults without known vitamin or mineral deficiencies.[2] It found that supplementation was associated with little or no benefit in preventing cancer, cardiovascular disease and death, with the exception of a small benefit for cancer incidence with multivitamin use.[2] Supplement doses and formulas differ from what is in a bottle of vitamin water, so these findings cannot be transferred directly. They do, however, provide little support for assuming that adding vitamins to an already adequate diet prevents major chronic diseases or premature death.

In practice, the vitamin deficiencies I see in my clinic are mainly vitamin D, folate and vitamin B12. In my experience, the folate and B12 deficiencies I see usually have an identifiable background, such as pregnancy, an underlying disease or heavy alcohol use. Thiamine deficiency is also not unusual among my patients with heavy alcohol use, and in emergency care they are often given thiamine by injection. These situations call for targeted treatment rather than a fortified drink. The folate need in pregnancy is large and is met with tablets, in amounts that, in my view, a vitamin water is unlikely to provide. With vitamin B12 deficiency, I consider it important to investigate the cause, for example pernicious anaemia or atrophic gastritis, and in my practice the supplementation is dosed by a physician. A vitamin water cannot replace that work-up.

Vitamin C Megadosing: What Became of Pauling’s Idea?

Vitamin C is the classic example of the belief that more is better. In 1970, Linus Pauling, a Nobel laureate in chemistry, wrote a book on vitamin C and the common cold, and he proposed that vitamin C doses should be at least 1 g/day.[3] A Cochrane review later pooled the placebo-controlled trials. In the general community (10,708 participants), regular vitamin C supplementation did not reduce the incidence of colds (risk ratio 0.97, 95% CI 0.94 to 1.00).[4] Regular supplementation shortened colds by 8% in adults, but in therapeutic trials, where vitamin C was started after symptoms began, there was no consistent effect on duration or severity.[4] The authors concluded that routine vitamin C supplementation is not justified in the general population.[4]

From a clinical perspective, most people already get enough vitamin C from their diet. I have never seen a case of scurvy in my own clinical work, and as far as I know it is very rare in Western countries.

The “Health Halo” Effect

The vitamins may matter more for marketing than for physiology. Nutrient content claims may lead consumers to mistakenly infer that a product is healthful regardless of its overall nutritional profile, a phenomenon known as the “health halo effect”.[5]

Three randomized online experiments with US adults tested this with sugar-sweetened fruit drinks. Across the three studies, participants who saw a “100% Vitamin C” claim on a fruit drink rated it as more healthful than those who did not see the claim (mean average differential effect 0.66), and they were also more interested in consuming it (mean average differential effect 0.38).[5] These experiments used fruit drinks, not vitamin water, so the findings cannot be transferred directly. In these fruit-drink experiments, a vitamin claim made the drink seem healthier to consumers.

The Sugar Question: Sweetened Vitamin Water Is a Sugar-Sweetened Beverage

A vitamin water with added sugar belongs to the same category as other sugar-sweetened beverages, whatever its label says about vitamins. That matters because the health effects of sugar-sweetened beverages have been examined in large meta-analyses and cohort studies.

In its scientific statement on dietary sugars, the American Heart Association identified soft drinks and other sugar-sweetened beverages as the primary source of added sugars in Americans’ diets.[6] It set a prudent upper limit at half of the discretionary calorie allowance, which for most American women is no more than 100 calories per day and for most American men no more than 150 calories per day from added sugars.[6] Checking the sugar figure for the whole bottle against these limits shows how much of a day’s allowance a single drink uses.

Weight Gain

A systematic review and meta-analysis of 32 original articles examined sugar-sweetened beverages and body weight.[7] In adult cohort studies, one daily serving increment was associated with 0.22 kg (random-effects model) and 0.12 kg (fixed-effects model) of weight gain over one year. In adult randomized controlled trials, adding sugar-sweetened beverages increased body weight by 0.85 kg.[7] The authors concluded that their review provides evidence that sugar-sweetened beverage consumption promotes weight gain in children and adults.[7]

Type 2 Diabetes

A meta-analysis of 17 cohorts (38,253 cases over 10,126,754 person years) found that higher consumption of sugar-sweetened beverages was associated with a greater incidence of type 2 diabetes, by 18% per one serving per day before adjustment for adiposity and by 13% after it.[8] The association remained after statistical adjustment for adiposity, although residual confounding cannot be excluded.

Mortality

In two large US cohorts, 37,716 men from the Health Professionals Follow-up Study and 80,647 women from the Nurses’ Health Study, consumption of sugar-sweetened beverages was associated with a higher risk of total mortality after adjusting for major diet and lifestyle factors.[9] Compared with drinking them less than once a month, drinking two or more per day was associated with a hazard ratio of 1.21 for total mortality and 1.31 for cardiovascular mortality.[9]

These are observational associations, not proof that any single drink causes disease. Taken together with the trial data on weight gain, though, they make a consistent case against regular consumption of sugar-sweetened beverages, and sweetened vitamin water is not exempt from that case.

One practical point is easy to overlook. If someone genuinely needed extra water-soluble vitamins, they would need them every day, and in my view drinking a sugar-sweetened beverage daily is a poor way to get them. I do not necessarily see harm in an occasional vitamin water, but regular or excessive intake of sugary drinks does not seem sensible to me, and it may also harm the teeth.

What About Zero-Sugar Vitamin Water?

Choosing a sugar-free version avoids the added sugar, although that alone does not establish the product’s long-term health effects. The evidence on artificially sweetened beverages is less clear-cut. In the diabetes meta-analysis, artificially sweetened beverages also showed a positive association with type 2 diabetes, but publication bias and residual confounding were indicated, and the authors judged the findings likely to involve bias.[8] The same authors still concluded that artificially sweetened beverages were unlikely to be healthy alternatives to sugar-sweetened beverages for preventing type 2 diabetes.[8]

In the mortality cohorts, artificially sweetened beverages were associated with total and cardiovascular mortality only in the highest intake category, the association was seen among women but not men, and the authors stated that it requires further confirmation.[9] A zero-sugar vitamin water avoids the added sugar of the sweetened version, but its added vitamins carry the same limited evidence of benefit for well-nourished people.

Hydration: Is Vitamin Water Better Than Plain Water?

Vitamin water is often chosen as a “better” way to hydrate. A randomized trial developed a beverage hydration index by giving 72 euhydrated, fasted men 1 L of still water or other common drinks and collecting urine for the next 4 hours.[10] An oral rehydration solution, full-fat milk and skimmed milk produced less urine than still water. Cumulative urine output after cola, diet cola, hot tea, iced tea, coffee, lager, orange juice, sparkling water and a sports drink was not different from water.[10]

Vitamin water was not tested in this trial, and the study was funded by the European Hydration Institute. In euhydrated men at rest, most of the ordinary drinks tested produced a similar 4-hour urine output to water. The trial did not examine vitamin-fortified drinks, so it offers no evidence that added vitamins improve hydration.

Is Vitamin Water Good for You as an Athlete?

Vitamin waters are often marketed to active people, with the idea that hard training should not go to waste because of vitamin deficiencies. In my view, vitamins generally help only when they correct a deficiency; without one, taking more of them is unlikely to improve athletic performance. Training may raise vitamin needs somewhat, but I do not see athlete status alone as a reason to take extra vitamins, because in my understanding athletes’ needs do not differ markedly from general intake recommendations. In my clinical experience, few patients drink vitamin waters regularly. It is more often an impulse purchase after training, or a bottle picked off the shelf on the assumption that the added vitamins make it especially healthy, much as sports drinks are often assumed to be healthy.

One research finding is worth knowing in this context. In the Cochrane review, five trials of 598 marathon runners, skiers and soldiers on subarctic exercise found that regular vitamin C supplementation was associated with a risk ratio of 0.48 for catching a cold.[4] The authors noted that vitamin C may be useful for people exposed to brief periods of severe physical exercise.[4] That finding concerns vitamin C supplements and cold risk, not athletic performance or vitamin water.

It is true that athletes may benefit from a higher vitamin C intake, but in my view this mainly concerns the risk of catching a cold. For an athlete who wants extra vitamin C for that reason, I would see a tablet as a more sensible option than vitamin water.

Carbohydrate During Exercise

Athletes have a genuine reason to drink carbohydrate during training, but it depends on the duration of the session. For exercise lasting approximately 1 hour, a mouth rinse or small amounts of carbohydrate can result in a performance benefit, and for more prolonged exercise (2 to 3 hours) the recommendation is approximately 60 g of carbohydrate per hour from a single carbohydrate source.[11]

Vitamin water is generally not formulated as a sports drink. Whether a given bottle can contribute to these targets depends on its carbohydrate and sodium content, which only the label can tell you. The added vitamins play no part in this role.

Dental Health

Sweetened drinks may also matter for teeth. In a cross-sectional study at the London 2012 Olympic Games, which recruited 302 athletes from 25 sports, 55% of athletes had dental caries and 45% had dental erosion, and 18% reported an impact of their oral health on training and performance.[12] Frequency of sports drink use was associated with dental erosion on the anterior teeth, but not on the posterior teeth or both combined.[12] The authors suggested that high caries levels in athletes might result from frequent carbohydrate intake and reduced salivary flow.[12]

This was a cross-sectional study of athletes attending a dental clinic, so it cannot show cause and effect. It does, however, suggest that drink choices deserve attention when it comes to athletes’ oral health.

In my view, repeatedly drinking sugary drinks in the hope of getting vitamins may well do more harm than good through dental erosion and caries. With a healthy diet, most people would not need extra amounts of these vitamins in the first place.

Practical Takeaways: Is Vitamin Water Good for You?

Read the label for the whole bottle. Sweetened vitamin water is a sugar-sweetened beverage. Compare its total sugar with the American Heart Association’s upper limit of no more than 100 calories per day for most women and 150 calories per day for most men from added sugars.[6]
The added vitamins add little for most people. In well-nourished adults, vitamin and mineral supplementation has shown little or no benefit for major health outcomes,[2] and the vitamins most often added to these drinks are ones that most young adults already get enough of.[1] A suspected deficiency is better assessed with a clinician than addressed with fortified drinks.
Plain water is a reasonable everyday choice. In a resting study, most of the common drinks tested produced a similar urine output to water, and the trial offers no evidence that added vitamins improve hydration.[10]
Zero-sugar versions are the lesser concern. They remove the sugar, though the evidence on artificially sweetened drinks is not fully settled.[8][9]
Athletes have better tools for long sessions. Carbohydrate needs during exercise depend on session duration,[11] and products designed for that purpose make the intake easier to plan.
Mind your teeth. In elite athletes, more frequent sports drink use was associated with erosion of the front teeth.[12]

Conclusion: Is Vitamin Water Good for You?

So, is vitamin water good for you? For most people, it is not the health drink its name suggests. The sweetened versions are sugar-sweetened beverages, a category linked to weight gain in trials and to higher rates of type 2 diabetes and mortality in large cohorts.[7][8][9] The added vitamins are mostly ones that well-nourished adults already get enough of, and supplementing them has shown little or no benefit for major outcomes.[1][2]

This matches what I see in practice. Vitamin water can provide some vitamins, but in my view it is not a very fit-for-purpose way to meet vitamin needs. Those needs are daily, and drinking vitamin water every day does not seem sensible to me: the sweetened versions add sugar, may harm the teeth and may contribute to weight gain, and the drink does not cover all vitamin needs in any case. A single bottle now and then is likely to have only a marginal effect on your overall health, so in the short term I see little harm, but also little benefit. With long-term daily use, I see more harm than benefit. If a vitamin deficiency is genuinely suspected, the more sensible route is to find out which vitamin is low and why, and to treat it specifically.

In the resting study cited here, most common drinks produced a similar urine output to plain water,[10] and plain water costs less and carries no sugar. In my view, reading the label, rather than the marketing, is the simplest way to decide where vitamin water fits in your own diet.

Is Vitamin Water Good for You? What the Research Says About Sugar, Vitamins and Hydration

Table of Contents

Key Takeaways

Introduction: Is Vitamin Water Good for You?

What Is Actually in Vitamin Water?

The Vitamin Question: Do Added Vitamins Help Healthy People?