Supplements: what do we actually need?
Updated: Sep 7
The shelf keeps growing. The honest answer is shorter than the shelf, and it starts with a blood test rather than a shopping list.
Every few months a new capsule becomes essential. Ashwagandha, then collagen, then a mushroom powder, then whatever comes next. The pattern is always the same: a real mechanism, a small study, a very large promise.
So let me answer the question I get most often, as precisely as I can. Not what could theoretically help, but what most people living in Switzerland, eating a varied omnivorous diet, actually have reason to take.
First: get your blood tested.
This is the part people skip, and it is the only part that makes the rest meaningful. Nutrient status is individual. It depends on what you eat, how much time you spend outside, your age, your cycle, your medication, whether you've been pregnant, whether you train, how your gut absorbs.
A blood panel turns guesswork into a decision. It tells you what to take, how much, and — just as usefully — what to stop buying. Ask your GP; most of the relevant markers are routine. Then retest after three to six months, because the point is to correct something, not to take it forever by default.
Omega-3 — year round, 250 to 500 mg EPA and DHA
Almost everything is individual. Two things are close enough to universal here that they hold for most people, and both are about geography rather than diet.
Vitamin D — October to March, 800 IE a day
Between roughly October and March, the sun in Switzerland sits too low for your skin to make meaningful amounts of vitamin D, no matter how much time you spend outside. That is not a lifestyle problem. It is latitude.
The numbers back it up: in the summer months around 80 % of the population is adequately supplied, while in the winter months more than 60 % fall below the recommended blood level of 50 nmol/l. Food can't close that gap — you'd need two portions of oily fish a day, or twenty eggs.
The Federal Nutrition Commission recommends 600 to 800 IE per day for adults, and 800 IE from age 60. I'd take 800 IE (20 µg) daily through the dark months, with a meal that contains some fat. For context on safety: the legally defined long-term maximum for supplements is 4000 IE per day, so 800 sits comfortably inside it.
Omega-3 — year round, 250 to 500 mg EPA and DHA
The reference intake for adults is 250 to 500 mg of EPA and DHA combined per day. This one you can genuinely eat: two portions of fish a week, one of them oily — salmon, herring, mackerel, sardines — averages out to about that.
If you don't eat fish twice a week, and most people I speak to don't, a supplement is the straightforward fix. 500 mg EPA and DHA daily, fish oil or algae oil if you eat plant-based. Walnuts, linseed and rapeseed oil give you ALA, which your body converts — but at a rate below 10 %, so it doesn't replace the long-chain forms.
What I take myself — and why that's a different claim.
The two above are recommendations. The next two are mine, and I want to keep the two categories apart, because a nutritionist's personal experience is still just one person's experience.
Magnesium glycinate
I had cramps for years. I tried several forms of magnesium and none of them changed anything. Magnesium glycinate was the one that worked — since I switched, the cramps are almost entirely gone.
I'll be honest about what that is and isn't. It's a sample size of one. The trials comparing magnesium forms are small and don't clearly crown a winner, so I can't tell you glycinate is objectively better. What I can tell you: if one form hasn't done anything for you, trying another is cheap, low-risk and reasonable. Don't conclude that magnesium doesn't work for you until you've tried more than one.
Creatine
Creatine is one of the best-researched supplements that exists — decades of trials, in men and, increasingly, in women. The strength effect is the solid part: you can lift more, and lifting more is what builds muscle over time. Three to five grams of creatine monohydrate a day, no loading phase needed, no timing rules.
The brain part is where I'd stay careful, because it's the part being oversold right now. There is real signal — a review of studies in older adults found five of six reporting a positive relationship with cognition, particularly memory and attention — but the authors call the evidence limited and ask for better trials. Creatine also doesn't cross the blood-brain barrier easily, which is why the cognitive studies tend to use higher doses than the 3 to 5 g used for muscle.
Water-soluble, fat-soluble: why the difference matters.
Beyond the four above, your blood values decide. And there's one distinction worth understanding before you add anything on a hunch, because it's the difference between wasting money and doing harm.
Water-soluble vitamins — the B group and vitamin C — dissolve in water. Take more than you need and most of the surplus leaves with your urine. The main cost of overdoing it is the price of the capsule.
Fat-soluble vitamins — A, D, E and K — behave differently. They are stored in the liver and in fat tissue rather than excreted, and an excess can build up to the point of toxicity. That is the real reason not to take them just in case: the surplus doesn't leave. Too much vitamin A has consequences for the liver and the skeleton; too much vitamin D raises blood calcium.
There is a second effect that often gets repeated as if it were the main one — that fat-soluble vitamins take each other's place. It's not nothing: vitamins D, E and K share absorption pathways in the gut, which explains the competition observed between them, and high-dose beta-carotene has been shown to lower vitamin E in the blood. Real, measurable, worth knowing. But it's the footnote, not the headline. Storage is the headline.
This is general information, not individual advice. If you're pregnant, breastfeeding, taking medication or managing a diagnosed condition, dosages and interactions need discussing with your doctor.
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