For many people, vitamin D in summer sounds like something you can happily shelve until autumn. In reality, it all depends on how much time you actually spend in the sun, what your work and training routine looks like, and whether you belong to a risk group.

Why are we talking about vitamin D in summer at all?

The Estonian summer is short and unpredictable. One week it’s warm, then it rains, then you’re back at work or in an indoor workout. There’s plenty of daylight, but that doesn’t automatically mean your body is producing enough vitamin D.

Honestly, this is where many people go wrong. If your vacation is spent on the beach, hiking or working in the garden, you may well get more sun.

The original idea behind this story was simple: an athlete can also belong to a risk group, especially if their sport and training take place indoors. The body uses vitamin D in several processes, and someone who trains shouldn’t track only calories, protein and recovery. Vitamin status matters too.

How does vitamin D work in the body?

Vitamin D helps the body absorb calcium. This is important for bones, teeth and the normal function of muscles. If your levels are low, you may feel tired, weak or generally flat. These signs alone don’t prove a deficiency, but they shouldn’t be brushed off entirely either.

You can get vitamin D from three places: the sun, food and, when needed, a supplement. The sun is the best-known source, but in Estonia’s climate it isn’t always reliable. In food, vitamin D3 is found in fatty fish, egg yolks, liver and cod liver oil, for example. Plant-based vitamin D2 exists too, but it’s usually considered less well utilized by the body.

Food can contribute, but relying on your menu alone is difficult. The original article pointed out, for example, that to get even a small daily amount you would have to eat very large quantities of eggs, cheese, liver or milk. The point stands: a typical menu may not cover your needs, especially if fish rarely lands on your plate.

Vitamin D in summer: who should pay particular attention?

The risk group includes people who spend little time outdoors. That covers older adults, office workers, shift workers and anyone whose day is spent mostly indoors. Athletes in indoor sports should think about it too. If you train in the gym even in summer, the sun isn’t doing the job for you.

Extra attention is also needed for pregnant women, infants and small children, rapidly growing teenagers, and people who have previously been found to have a vitamin D deficiency. In these cases, don’t set your dose by feel. Your family doctor or a blood test will give a much more reliable picture.

A simple truth: if you don’t know your levels, you’re really just guessing. Fatigue can come from lack of sleep, too much training volume, stress or iron deficiency. Vitamin D may be one piece of the puzzle, but it isn’t the only answer to everything.

What should you practically do about vitamin D in summer?

Start with your own day. If you’re outdoors every day, your skin gets moderate sun and you eat fish regularly, the situation may be better. If you mostly move between home, car, work and the gym, the picture is different. Daylight through a window is not the same as sun on your skin.

In summer you don’t have to automatically add everything in, nor automatically stop. It makes sense to look at your habits and, if needed, get a blood test. For adults, daily amounts of 10 mcg or 400 IU are often mentioned, and for risk groups 20 mcg or 800 IU or more, but your personal needs may differ.

If you choose a supplement, check the amount, the form and the directions for use on the package. Vitamin D is fat-soluble, so it’s often taken with food. If you take medication, are pregnant or the doses are high, talk to your doctor first.

You can see Regina Krukovskaja’s original Instagram post here: Regina Krukovskaja Insats HERE.

FAQ: vitamin D in summer

Does a sunny vacation cover your needs for the whole summer?

Not always. After a sunny period your levels may be better for a while, but that may not last the whole summer or until autumn. What matters is what happens in your ordinary week.

Does fatigue definitely mean a vitamin D deficiency?

No, it doesn’t. Fatigue has many causes. If it persists, look at your sleep, training load and nutrition, and get a blood test if needed.

Does an athlete need more vitamin D in summer?

In some cases, yes, especially if your training sessions take place indoors and you spend little time moving outdoors. The definitive answer, though, comes from your blood levels, not just your training plan.

Author: Regina Krukovskaja

Come and train! ArtGym