Which nutrients does the body need in summer?

High temperatures, intense sun exposure and more time spent outdoors place particular demands on the body in summer. Some micronutrients – including magnesium, potassium, vitamin C, vitamin E and carotenoids – deserve special attention. In this blog article you will learn why nutrient requirements can change partly in summer and which factors play a role. We also introduce the most important vitamins and minerals for summer and show which foods can best supply your body on hot days. Finally, you will receive ten practical tips to specifically support your nutrient intake during the summer months.

Why do nutrient requirements change in summer?

To keep body temperature constant and protect the organism from the effects of heat and intense sun exposure, the body must make specific adjustments in summer. One of the most important responses is increased sweating. However, sweat not only causes fluid loss but also electrolytes such as magnesium and potassium, which are important for normal muscle and nerve function, among other things.¹ In people who remain physically active or do outdoor sport despite high temperatures, the loss of water and minerals is often even greater.

Stronger UV radiation in summer also affects metabolism. UV radiation promotes the formation of free radicals, which can cause oxidative stress in cells.² To neutralise these reactive oxygen species, the body needs antioxidant nutrients such as vitamin C, vitamin E and carotenoids. At the same time, the skin as an outer protective barrier is more heavily stressed by UV radiation. Antioxidant vitamins and plant secondary metabolites can make an important contribution to maintaining normal skin function – although, if necessary, they do not replace appropriate sun protection.

Many people also change their general eating habits in summer. Heavy meals are often replaced by lighter dishes and foods such as salads, fruit or cold soups. Mineral-rich foods such as wholegrain products or legumes are often eaten less frequently. This does not mean that the need for micronutrients automatically increases in summer. However, certain vitamins and minerals deserve special attention during the hot season to support optimal nutrient supply.

The most important vitamins and minerals for hot days

Not all vitamins and minerals are required in larger amounts during the summer months. However, some micronutrients deserve particular attention because they, for example, are lost through increased sweating or can help the body better cope with summer stresses such as heat, physical activity and UV radiation. Below we briefly present a selection of the most important summer nutrients with their main health-related claims – so-called “Health Claims”³ – and food sources.

1. Magnesium – essential for muscles and electrolyte balance

As one of the most abundant minerals in the human body, magnesium is involved in more than 300 enzymatic reactions.⁴ Among other things, it plays a central role in energy metabolism, in the transmission of signals between nerves and muscles and in the normal function of muscles. Magnesium is also an essential component of the electrolyte balance and helps maintain the balance between the various minerals in the body.

Magnesium becomes particularly relevant in summer because more magnesium is lost through sweating. People who regularly exercise, do physical work or spend extended periods in the heat can excrete increased amounts of magnesium. At the same time, fluid and electrolyte losses can promote muscle cramps or quicker fatigue. Although a muscle cramp is not necessarily due to magnesium deficiency, adequate supply of this mineral is sensible, especially during intense physical exertion.

Some of the best sources of magnesium include pumpkin seeds, cashew nuts, almonds, oats, wholegrain products and legumes.

Magnesium…

• contributes to electrolyte balance
• contributes to normal muscle function
• contributes to the reduction of tiredness and fatigue
• contributes to normal energy-yielding metabolism

2. Potassium – an important electrolyte in summer

Among the body's electrolytes, potassium plays a key role. Together with sodium, potassium regulates fluid and electrolyte balance and is involved in the transmission of electrical signals between nerve cells. Potassium also influences muscle contraction and contributes to the maintenance of normal blood pressure.

Because potassium, like magnesium, is lost through sweat, adequate intake should be ensured, especially on hot days. With heavy sweating or longer periods of physical activity, fluid and electrolyte losses can be particularly pronounced. A potassium-rich diet helps the body to keep fluid balance stable and to maintain normal muscle and nervous system function. Particularly practical: many potassium-rich foods are also high in water and are therefore ideal for hot summer days.

Foods high in potassium include potatoes, bananas, apricots, avocados, spinach and legumes (e.g. cooked white beans).

Potassium…

• contributes to normal functioning of the nervous system
• contributes to normal muscle function
• contributes to the maintenance of normal blood pressure

3. Vitamin C – support for skin and immune system

Vitamin C is one of the body's most important water-soluble antioxidants. It performs numerous functions in metabolism and is indispensable for the formation of collagen – an essential component of skin, blood vessels, bones and connective tissue. At the same time, vitamin C protects body cells from oxidative stress and supports normal immune function.

The special relevance of vitamin C in summer is linked to the fact that intense UV radiation can promote the formation of free radicals. These highly reactive oxygen species can damage cellular components and cause oxidative stress. Vitamin C helps neutralise these free radicals and supports the body's natural defence mechanisms. In addition, it regenerates oxidised vitamin E and enhances its antioxidant effect. As it can improve the absorption of non‑haem iron from plant foods, vitamin C is also particularly important for people following predominantly plant-based diets.

Suitable natural sources of vitamin C include peppers, berries, kiwifruit, broccoli and citrus fruits.

Vitamin C…

• contributes to normal immune system function
• helps protect cells from oxidative stress
• contributes to normal collagen formation for the normal function of the skin
• increases iron absorption

4. Vitamin E – protection of cell membranes

Vitamin E is an essential fat‑soluble antioxidant that particularly protects the polyunsaturated fatty acids in cell membranes from oxidative damage. In this way it contributes to the stability and functionality of cells. Together with vitamin C, vitamin E forms an important antioxidant defence system that protects body cells from the harmful effects of free radicals.

Since UV radiation can promote the formation of free radicals in the skin, vitamin E comes into focus during the summer months. Through its antioxidant properties, vitamin E helps protect cell membranes from oxidative stress. It is particularly effective in combination with vitamin C, which can regenerate oxidised vitamin E and thus prolong its antioxidant action. Foods that contain relevant amounts of vitamin E include sunflower seeds, almonds, hazelnuts, avocados and high‑quality vegetable oils (e.g. wheat germ oil, safflower oil).

Vitamin E…

• helps protect cells from oxidative stress

5. Carotenoids – natural support for the skin barrier

Carotenoids are natural plant pigments that give many fruits and vegetables their yellow, orange, red or dark green colour. The best-known representative is beta‑carotene (or β‑carotene), which acts as a provitamin A and can be converted into vitamin A in the body as needed. There are numerous other carotenoids such as lycopene, lutein or zeaxanthin, which also possess antioxidant properties.

Carotenoids are of particular interest in summer because of their importance for the skin. Studies show that certain carotenoids can accumulate in the skin and act as antioxidants there.⁵ In doing so, they support the skin's natural defence mechanisms against UV‑induced oxidative stress. As already described, beta‑carotene also provides a precursor for vitamin A, which contributes to the maintenance of normal skin. Nevertheless: carotenoids are not a sunscreen and cannot replace measures such as sunscreen, protective clothing or staying in the shade.

Carotenoids are mainly found in plant foods such as carrots, sweet potatoes, pumpkin, peppers, tomatoes, spinach, kale and broccoli.

Vitamin A (from beta‑carotene)…

• contributes to the maintenance of normal skin
• contributes to normal immune system function

Well supplied through the summer: 10 practical tips for improved nutrient intake

You should ideally not wait until the first warning signs such as fatigue, muscle cramps or circulatory problems appear before thinking about nutrient supply in summer. A preventive approach is much more recommendable: one that helps the body better cope with the specific stresses of heat, intense sun exposure and increased sweating. The following tips can help you to supply your body optimally during the summer months.

• Prioritise adequate fluid intake: As temperatures rise, fluid loss through sweat usually increases significantly. For this reason, it is important to drink regularly throughout the day – preferably before a marked feeling of thirst develops. As confirmed by the German Nutrition Society (DGE), mineral water as well as (unsweetened) herbal and fruit teas are the best thirst‑quenchers.⁶
• Drink mineral‑rich water: Because not every mineral water contains the same amount of minerals, it's worth taking a closer look at the label. Particularly magnesium‑ or calcium‑rich mineral waters can make a valuable contribution to daily intake. After heavy sweating, for example after endurance sport, mineral‑rich water can help the body to replace fluid and mineral losses.
• Eat plenty of seasonal fruit: Popular summer fruits such as berries, cherries, apricots, peaches or watermelon not only provide valuable vitamins and plant secondary metabolites but also consist largely of water. They therefore contribute both to hydration and to the intake of antioxidant micronutrients. Make use of the wide variety of regional and seasonal fruit during the summer months.
• Consume vegetables raw or gently cooked: Many heat‑sensitive vitamins – especially vitamin C – can be partly lost during long cooking. Prepare vegetables as raw or only briefly cooked, steamed or poached where possible. This preserves as many vitamins, minerals and plant secondary metabolites as possible.
• Regularly include nuts and seeds: Nuts and seeds are among the most nutrient‑dense foods. In addition to magnesium, vitamin E and high‑quality fatty acids, they also provide plant protein. You don't have to empty a whole packet: a small handful of almonds, walnuts, pumpkin seeds or sunflower seeds per day can meaningfully complement your nutrient intake.
• Replenish electrolytes after heavy sweating: After intense training sessions, hikes or long periods in the heat, the body loses not only water but also important electrolytes such as magnesium, potassium and sodium. It is sensible to replace these afterwards. Suitable options include mineral‑rich drinks as well as potassium‑ and magnesium‑rich foods such as potatoes, bananas, legumes or nuts.
• Pay attention to your protein intake: Protein is important not only for muscle building but also for numerous metabolic processes and the body's regeneration.⁷ In summer, heavy meals are often replaced by lighter dishes, which can lead to insufficient protein intake. Make sure to complement salads and other light dishes with protein sources such as legumes, eggs, fish, lean meat, tofu or dairy products.
• Prefer “colourful plates”: The more colourful the foods on your plate, the greater the variety of vitamins, minerals and plant secondary metabolites is likely to be. In particular, orange, red, green and purple fruits and vegetables provide valuable carotenoids, polyphenols and other antioxidant compounds. A varied palette of colours is therefore a good and practical guide to nutrient‑rich eating.
• Consume fat‑soluble vitamins with some fat: Fat‑soluble vitamins A, D, E and K can only be absorbed optimally if some fat is present. Combine vegetables, for example, with high‑quality vegetable oil, nuts, avocado or seeds. Small amounts of fat are sufficient to significantly improve absorption of fat‑soluble vitamins.
• Plan light but nutrient‑dense meals: Many people experience reduced appetite in high temperatures. Rather than skipping meals, opt for easily digestible yet nutrient‑dense foods. Salads with legumes, wholegrain products, vegetables or yoghurt with fresh fruit supply important micronutrients without unduly burdening the body in the heat.

Disclaimer

This article does not replace treatment by a qualified practitioner. The basis of this contribution is studies and current literature. It must not be used for self‑diagnosis or self‑treatment. Discuss any inspirations from this article with a practitioner you trust, if necessary.

Biography

Katharina Korbach regularly writes blog posts for the Narayana Verlag on medicinal plants and natural active ingredients. She developed an interest in language early on and began writing her own literary texts. A serious illness during her final school years prompted intensive engagement with health and nutrition topics that continues to this day. After repeated failures of conventional medical treatments, she opted for a more self‑empowering naturopathic therapeutic approach. A plant‑based diet was an important key on her path to recovery.

Sources

1. Baker LB. Sweating Rate and Sweat Sodium Concentration in Athletes: A Review of Methodology and Intra/Interindividual Variability. Sports Med. 2017 Mar. https://pubmed.ncbi.nlm.nih.gov/28332116/.
2. Bosch R, Philips N, Suárez-Pérez JA, Juarranz A, Devmurari A, Chalensouk-Khaosaat J, González S. Mechanisms of Photoaging and Cutaneous Photocarcinogenesis, and Photoprotective Strategies with Phytochemicals. Antioxidants (Basel). 2015 Mar 26. https://pmc.ncbi.nlm.nih.gov/articles/PMC4665475/.
3. EFSA (2006): Health Claims. https://www.efsa.europa.eu/en/topics/topic/health-claims (accessed: 28.06.2026).
4. Al Alawi AM, Majoni SW, Falhammar H. Magnesium and Human Health: Perspectives and Research Directions. Int J Endocrinol. 2018 Apr 16. https://pmc.ncbi.nlm.nih.gov/articles/PMC5926493/.
5. Stahl W, Sies H. β-Carotene and other carotenoids in protection from sunlight. Am J Clin Nutr. 2012 Nov. https://pubmed.ncbi.nlm.nih.gov/23053552/.
6. DGE (2000): Wasser. https://www.dge.de/wissenschaft/referenzwerte/wasser/ (accessed: 28.06.2026).
7. Morton RW, Murphy KT, McKellar SR, Schoenfeld BJ, Henselmans M, Helms E, Aragon AA, Devries MC, Banfield L, Krieger JW, Phillips SM. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. Br J Sports Med. 2018 Mar. https://pubmed.ncbi.nlm.nih.gov/28698222/.