Summer Vitamins and Supplements: Five Nutrients to Consider
- , by SANUSq Research team
- 13 min reading time
Every summer brings a new wave of "seasonal" pills and cleanses. The truth about summer vitamins is simpler: in hot weather your body mostly needs water, varied food, decent sleep and a few targeted adjustments. Here are the five nutrients worth thinking about, in order of real importance, including one that surprises most people.
Summer vitamins: start with what you actually need
Summer asks something different of the body rather than something extra. You sweat more, spend more time outdoors and often sleep less well. So the priorities are practical: replacing lost water and minerals, eating plenty of fresh produce, protecting your skin and keeping cool. Supplements have a targeted place, and the first item on our list doesn't come in a bottle at all.
1. Water and electrolytes: hydration comes first
The most important summer "supplement" is water. Sweating is how the body sheds heat, and sweat carries away water and minerals, mainly sodium, with smaller amounts of potassium and other electrolytes.
In a comprehensive review of sweat gland function, Baker (2019) describes sodium chloride as the main electrolyte lost in sweat. People with very salty sweat face a higher risk of salt imbalance during long periods of heavy sweating, whereas losses of trace minerals and vitamins in sweat appear to pose minimal risk.
A few simple habits cover most of what you need:
- Drink steadily through the day, rather than waiting until you feel thirsty.
- Check the colour of your urine. Pale straw is generally a good sign; dark yellow suggests you need to drink more.
- Eat water-rich foods. Cucumber, watermelon, melon, tomatoes and courgettes supply fluid along with potassium.
- Balance coffee and alcohol with water. Alcohol in particular increases fluid loss, so it is best kept modest on very hot days.
For most people, water and ordinary meals replace sodium and potassium well. During long exercise in the heat or after heavy sweating, an electrolyte drink can complement plain water. Potassium contributes to normal muscle function and to the normal functioning of the nervous system, and fruit and vegetables are the easiest source.
If you have kidney or heart disease, or take diuretics or other blood pressure medicines, check with your doctor before using electrolyte or potassium supplements.
Know the warning signs of heat illness
Headache, dizziness, weakness, cramps, nausea and confusion can signal heat illness. Move somewhere cool, loosen clothing, sip water and rest. If symptoms are severe, if the person stops sweating, becomes confused or faints, or if things do not improve quickly, seek urgent medical help.
A Lancet review by Ebi et al. (2021) found that hot weather and heat extremes increase illness and death, and also affect pregnancy outcomes, mental health and the ability to work. The authors stress that many of these risks are preventable.
2. Magnesium for hot, active days
Magnesium is one of the minerals lost in sweat, and needs may rise for people who are very active or who sweat heavily. It has several roles that are recognised in EU law: magnesium contributes to electrolyte balance, to normal muscle function and to the reduction of tiredness and fatigue. That makes it worth keeping an eye on in summer.
In a review of magnesium and exercise, Nielsen and Lukaski (2006) concluded that strenuous exercise appears to increase losses of magnesium in urine and sweat, which may raise requirements by around 10–20%. They also noted that supplementation benefited performance only in people whose magnesium status was low; in active people with adequate levels, it had not been shown to enhance performance.
Food comes first: dark leafy greens, nuts and seeds, pulses, wholegrains and dark chocolate. The signs of a shortfall, such as tiredness, cramps, irritability or poorer sleep, are not specific and have many other causes. So rather than supplementing blindly, improve your diet first and consider a supplement if intake stays low or needs are high, ideally with professional advice.
If you have kidney disease, speak to your doctor before taking magnesium. High doses can loosen the stools, and magnesium can reduce the absorption of some antibiotics and osteoporosis medicines, so leave a gap of a few hours between them.
3. Vitamin C for skin and antioxidant support
Sun and heat put the skin through its paces, and sunlight exposure increases oxidative stress in skin cells. Vitamin C is relevant here in several authorised ways: it contributes to the protection of cells from oxidative stress, to normal collagen formation for the normal function of the skin, and to the normal function of the immune system.
In a review of vitamin C and skin health, Pullar et al. (2017) explain that normal skin contains high concentrations of vitamin C, which supports collagen production and antioxidant defences. The authors note that the evidence comparing dietary intake with vitamin C applied to the skin is limited, and identify where better research is still needed.
Citrus fruit, kiwis, strawberries, peppers and tomatoes are rich in vitamin C. Some people also use a supplement, such as our Liposomal Vitamin C + Glutathione.
One clear point: no vitamin or supplement replaces sun protection. Shade, covering up with a hat and clothing, avoiding the midday sun and using a broad-spectrum sunscreen remain the essentials.
What about "tanning pills" and beta-carotene?
Beta-carotene, the orange pigment in carrots and apricots, is often promoted to "prepare" skin for the sun. The research is limited and does not change the advice above.
A meta-analysis by Köpcke and Krutmann (2008) pooled seven studies and found that beta-carotene supplementation was associated with some reduction in sunburn, but only after at least 10 weeks of use. In a later review, Stahl and Sies (2012) noted that the protection measured from dietary carotenoids is considerably lower than that achieved with topical sunscreens.
These are research findings, not a substitute for sunscreen, shade or covering up. Smokers and former smokers should avoid high-dose beta-carotene supplements altogether.
4. Omega-3 for year-round balance
Omega-3 fatty acids are not seasonal, but they remain worthwhile all year, especially as many modern diets provide plenty of omega-6 and relatively little omega-3. Rebalancing through food is a long-term goal rather than a summer one.
Oily fish such as sardines, mackerel and salmon provide EPA and DHA, which contribute to the normal function of the heart (with a daily intake of 250 mg). Plant sources such as linseed, rapeseed oil, walnuts and sacha inchi provide alpha-linolenic acid (ALA), which contributes to the maintenance of normal blood cholesterol levels (with a daily intake of 2 g). If you prefer a plant source, our Sacha Inchi Oil Capsules are one option.
5. Vitamin D: the summer twist
Here is the surprise. In winter, vitamin D is a genuine priority. Summer is the season when your skin makes the most of it, so for many people vitamin D is less of a concern now than at any other time of year.
Hyppönen and Power (2007) measured vitamin D levels in 7,437 British adults aged 45. Levels below 40 nmol/L were found in 46.6% of participants in winter and spring, compared with 15.4% in summer and autumn, showing how strongly the seasons shape vitamin D status.
Vitamin D contributes to the maintenance of normal bones and to the normal function of the immune system, so the aim is to avoid running short across the year: make the most of summer daylight and, where needed, use a supplement in the darker months, with a doctor's advice if you have risk factors such as darker skin or little time outdoors.
That does not mean skipping sun protection to "top up". Short periods of sensible exposure are enough, and the risks of too much sun are very real. You can protect your skin and still keep a healthy vitamin D status.
A systematic review by Neale et al. (2019) found little evidence that sunscreen lowers vitamin D levels when used in real-life settings. Field trials of daily sunscreen showed no effect, although the sunscreens tested had moderate protection, and the authors noted that very high-SPF products have not yet been studied in this way.
Who needs extra care in the heat
Older people feel thirst less and can dehydrate more quickly, young children are especially vulnerable to heat, and some conditions and medicines, including diuretics and heart or blood pressure treatments, change the body's water and salt balance.
In a narrative review, Meade et al. (2020) describe how ageing impairs the regulation of body temperature, blood pressure and hydration during heat exposure. They note that older adults with common chronic conditions such as heart disease, high blood pressure, type 2 diabetes or chronic kidney disease are particularly vulnerable during heatwaves.
For these groups, the priority is regular drinking, keeping cool and checking on them during hot spells, not a summer course of supplements. Electrolyte products should be agreed with a doctor first.
What to keep in mind, and what to ignore
Be wary of "summer deficiencies" that supposedly need urgent correction, or of seasonal cleanses: your liver and kidneys clear waste continuously. Summer rewards simple habits: drink enough, eat a varied and colourful diet, protect your skin, sleep as well as the heat allows and use supplements only where there is a real need. Magnesium on sweaty days, vitamin C for skin and immune support, and omega-3 for overall balance can have a sensible place. A cupboard of "summer special" capsules does not.
Frequently asked questions
What are the best supplements for summer?
The most important summer essential isn't a supplement: it is staying well hydrated alongside a varied diet. After that, magnesium is often the most relevant if you sweat a lot, since it contributes to electrolyte balance and the reduction of tiredness and fatigue.
Should I take vitamin D in summer?
Usually less than in winter, because summer sunlight lets your skin make vitamin D. The aim is to avoid running low across the year; whether you need a supplement, especially outside the sunny months, is worth discussing with your doctor.
Why is magnesium useful in summer?
Some magnesium is lost in sweat, and needs can rise with heat and activity. Magnesium contributes to normal muscle function and the reduction of tiredness and fatigue, which is helpful on active summer days. Food sources come first.
Can any supplement protect my skin from the sun?
No supplement replaces sun protection. Some studies have linked long-term beta-carotene use with slightly less sunburn, but the effect is far smaller than sunscreen. Shade, clothing, a hat and broad-spectrum sunscreen come first.
Is water enough when it is very hot?
Often, yes. During prolonged exercise or heavy sweating in strong heat, a drink with electrolytes can help alongside water. If you feel faint, dizzy, confused or very weak, get somewhere cool and seek medical help promptly.
Do older people need special care in summer?
Yes. Older people feel thirst less and can dehydrate faster. Regular drinking and staying cool matter most; check with a doctor before using electrolyte or other supplements, especially if taking heart or blood pressure medicines.
Magnesium for the summer months
Magnesium in a liposomal liquid form, taken as an easy daily serving.
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References
- Baker LB. Physiology of sweat gland function: the roles of sweating and sweat composition in human health. Temperature (Austin). 2019;6(3):211–259. PMID 31608304
- Ebi KL, Capon A, Berry P, et al. Hot weather and heat extremes: health risks. Lancet. 2021;398(10301):698–708. PMID 34419205
- Nielsen FH, Lukaski HC. Update on the relationship between magnesium and exercise. Magnesium Research. 2006;19(3):180–189. PMID 17172008
- Pullar JM, Carr AC, Vissers MCM. The roles of vitamin C in skin health. Nutrients. 2017;9(8):866. PMID 28805671
- Köpcke W, Krutmann J. Protection from sunburn with beta-carotene — a meta-analysis. Photochemistry and Photobiology. 2008;84(2):284–288. PMID 18086246
- Stahl W, Sies H. β-Carotene and other carotenoids in protection from sunlight. American Journal of Clinical Nutrition. 2012;96(5):1179S–1184S. PMID 23053552
- Hyppönen E, Power C. Hypovitaminosis D in British adults at age 45 y: nationwide cohort study of dietary and lifestyle predictors. American Journal of Clinical Nutrition. 2007;85(3):860–868. PMID 17344510
- Neale RE, Khan SR, Lucas RM, Waterhouse M, Whiteman DC, Olsen CM. The effect of sunscreen on vitamin D: a review. British Journal of Dermatology. 2019;181(5):907–915. PMID 30945275
- Meade RD, Akerman AP, Notley SR, et al. Physiological factors characterizing heat-vulnerable older adults: a narrative review. Environment International. 2020;144:105909. PMID 32919284
Read more on the blog
- Be Sure to Drink Plenty of Water →
- Magnesium for Muscle Cramps: Does It Work? →
- Skin Health From Within: Key Nutrients for a Healthy Glow →
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The team at SANUSq.
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The health information in this article is provided for educational purposes only. Consult your healthcare professional before making any medical decisions.
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