Guides & Knowledge
Clear articles on intake, dosage and effects of food supplements.
Hawthorn: interactions with medicines
Digoxin, beta blockers, anticoagulants: what has actually been studied in humans on hawthorn and medicines — and when a doctor needs to be asked.
Hawthorn: the plant, its species, the part used
Hawthorn is not one species but a genus. Which plant parts the pharmacopoeia knows, which one ends up in the capsule, and why that is not the same thing.
Buying hawthorn: what actually makes two packs comparable
Comparing two hawthorn packs: why the milligram figure alone says nothing, how to work out the price per month, and what the label has to state.
Hawthorn: tea, tincture or tablet?
Infusion, tincture, powder, dry extract: how much plant sits behind each daily dose, what the solvent changes, and why milligrams are not comparable.
Hawthorn extract: what 20:1 actually means
20:1, 4–7:1, 1:20 — what a drug-extract ratio tells you, why a high number does not mean stronger, and how to spot a label that says something.
Taking hawthorn: timing, duration, course
Is there a best time to take hawthorn? What the EU monograph says about splitting doses and course length — and how much of it applies to a supplement.
Silymarin: what is in milk thistle extract
Silymarin is not one substance but a mixture. What the milligrams on the pack mean, and why two measuring methods produce two different numbers.
Milk thistle and medication: interactions
Silymarin inhibits CYP3A4 and UGT1A1 in the test tube, yet almost nothing showed up in people. What the studies found and where caution still belongs.
Milk thistle or artichoke: the difference
Both are thistles and stand side by side on the shelf. What separates milk thistle from artichoke botanically, in the plant part used and in the extract.
Milk thistle with inulin: what the 100 mg mean
A milk thistle tablet also holds 100 mg of inulin from chicory root. What the fibre does there, how to place the amount and what it does not deliver.
Milk thistle quality: how to recognise it
Plant part, extract statement, silymarin per daily portion, batch analysis: which details on a milk thistle pack mean something — and what market surveys found.
Milk thistle: the plant, its origin and its seeds
Milk thistle comes from the Mediterranean. What belongs to it botanically, which part ends up in the supplement and what it has traditionally been used for.
Buying milk thistle: mg of silymarin and price per month
Which number on a milk thistle pack is comparable, why 1,000 mg of powder is less than 100 mg of extract, and how to work out the price per month.
Milk thistle: tea, tincture, capsule or tablet?
Tea, tincture, capsule, tablet — how much silymarin each form delivers, why water is the poorest solvent and what really counts between capsule and tablet.
Milk thistle 20:1 or 80 %: what the label means
Extract ratio and silymarin content are two different numbers. What 20:1 states, what 80 % means and how to read the two of them together.
Taking milk thistle: timing, duration, fat
Before or after eating, one dose or three, with oil or without — what the EMA monograph sets out for taking milk thistle, and what it leaves open.
Magnesium in combination supplements: how much?
Combination supplements often state exactly 56.25 mg of magnesium. Why that is no accident, how to convert compound into element, and what has to be added up.
Too much chromium: limits and chromium(III) vs (VI)
There is no tolerable upper level for chromium. What the EFSA guidance value of 250 µg means, where the BfR's 60 µg come from and why chromium(VI) differs.
Chromium and sugar cravings: what is proven
Chromium is advertised as a remedy for cravings for sweets. What EFSA assessed and rejected, what the studies show and which doses lie behind them.
How much chromium per day: 40 µg label, 30–100 µg estimate
The pack states 40 µg as a reference value, the DGE gives 30 to 100 µg. Why there is no real requirement figure for chromium, and what that means when buying.
Chromium and exercise: what the claims allow
Chromium is sold as a muscle and definition aid. Two claims are authorised, both about metabolism — what the training studies found, and what they did not.
Chromium deficiency: what is actually documented
In humans, chromium deficiency is documented only under long-term intravenous feeding. Why a blood test cannot settle the question, and what to look at instead.
Chromium in foods: table values and real portions
Broccoli, wholegrain, nuts: what European measurement data show about chromium in foods, why the figures vary so widely and where the intake really comes from.
Buying chromium: µg, form and combination products
How to judge a chromium supplement: which label details are mandatory, why µg of chromium is not µg of compound, and how to add up several sources.
Chromium forms: picolinate, chloride and yeast
Six chromium compounds are permitted in food supplements. What separates picolinate, chloride and chromium yeast — and what the label really tells you.
Taking chromium: timing, meals and spacing
Morning or evening, on an empty stomach or with food? What measurably shifts chromium absorption — and why the time of day plays the smallest part in it.
Chromium and blood sugar: what the claim covers
What the authorised claim on chromium and normal blood glucose levels means, what it does not say — and how the EFSA read the evidence in 2010 and 2014.
Too much zinc: the 25 mg limit and what it means
The tolerable upper intake level for zinc is 25 mg a day. Where the figure comes from, what it includes — and why exceeding it does not mean poisoning.
Zinc on a vegan diet: which column applies
Vegan does not automatically mean the high phytate level. How grain preparation decides whether 8 or 10 mg of zinc a day is the benchmark — with a sample day.
Zinc and copper: what the ratio really means
8:1, 15:1 — there is no official figure for the zinc-copper ratio. But there is a reason why the upper level for zinc was set at 25 mg a day.
Zinc daily requirement: 7 to 16 mg — who needs what?
Zinc needs depend on sex and phytate intake. What the D-A-CH reference values say, what food actually delivers and why 10 mg on the label means something else.
Zinc and exercise: what is proven — and what is not
Sweat carries off around 0.5 mg of zinc per hour of training. What that means for requirements — and why no authorised statement mentions muscles.
Zinc-rich foods: table and the phytate brake
Which foods supply how much zinc per 100 g — and why the table is only half the answer once wholegrain and pulses are on the plate.
Buying zinc: price per day, not price per milligram
With zinc the daily amount is capped, so more milligrams for your money is no advantage. How to compare packs properly and what the label has to tell you.
Zinc for skin, hair and nails: what may be said
Three sentences are officially approved for zinc — on skin, hair and nails. What “maintenance” means, and from which amount they may appear on a pack.
Zinc forms compared: what counts on the label
Gluconate, bisglycinate, picolinate, oxide: the zinc share ranges from 14 to 80 per cent. What the label has to state and what really differs in absorption.
Taking zinc: timing, meals and spacing
On an empty stomach more zinc is absorbed, with a meal it is better tolerated. What the gaps to iron and calcium really achieve — with the measured figures.
Too much vitamin B12: no upper limit, still 25 µg
No tolerable upper intake level was ever derived for vitamin B12. Why the BfR proposes 25 µg all the same — and where the surplus actually goes.
Vitamin B12 on a vegan diet: why a supplement belongs
Vegan is the one diet for which the DGE considers a B12 supplement mandatory. Why algae, sauerkraut and organic oat drink do not close the gap.
Vitamin B12 and folic acid: why the gap gets hidden
Both show the same blood count, but often only one is missing: why folic acid can mask a B12 deficiency — and where the 1,000 µg upper limit comes from.
Vitamin B12 daily requirement: 2.5 µg NRV, 4 µg reference
The pack says 2.5 µg, the German reference value is 4 µg, the tablet holds 1,000 µg. Which of the three is the daily requirement — and which is not.
Spotting a vitamin B12 deficiency: serum, holo-TC, MMA
A normal B12 value in the blood does not rule out a deficiency. What serum B12, holo-TC and methylmalonic acid each show — and in which order they change.
Vitamin B12 foods: what one portion delivers
Four everyday portions cover the reference value of 4 µg. What milk, egg, cheese and fish actually contribute — and why algae do not count.
Buying vitamin B12: price per month, not per µg
1,000 µg on the tin says little about what arrives. What makes a B12 pack comparable: days per tin, the form in the ingredients, mandatory label details.
Vitamin B12 forms: cyano-, methyl-, hydroxocobalamin
Four B12 forms are approved for food supplements. What sets them apart chemically, what the body makes of them — and what the label says.
Taking vitamin B12: timing, stomach acid, metformin
Morning or evening, on an empty stomach or with food, a gap to metformin? What actually decides how much B12 arrives — and what only sounds like a rule.
Vitamin B12 absorption: intrinsic factor and the 1 % rule
The active uptake route for vitamin B12 is full at around 1.5 µg per meal. What happens beyond that, why tablets hold 1,000 µg and who absorbs less.
Too much selenium: where the limit lies
EFSA sets 255 µg a day, the BfR proposes 40 µg for supplements. Why the gap between requirement and upper limit is so narrow with selenium.
Selenium on a vegan diet: plant sources
Selenium can be covered from plants alone, but the figures vary more than for any other trace element. What measurements show and what actually matters.
Selenium and iodine: why they are named together
Both belong to the thyroid, but with different jobs. What is short in Germany, what is enough — and why the order iodine before selenium matters.
Selenium daily requirement: 55, 60 or 70 µg?
The label says 55 µg, the DGE names 60 and 70 µg, EFSA says 70. Where the three figures come from — and why European soils have a say in it.
Selenium and the thyroid: what the claim covers
“Selenium contributes to normal thyroid function” is authorised. What that sentence means, why iodine is the raw material — and what large trials found.
Selenium deficiency: what lab values show
Selenium is in no standard blood panel. Which markers exist, what they actually measure — and why a low value is not automatically a deficiency.
Selenium in foods: table and portions
Which foods supply selenium, how much a usual portion adds — and why a selenium table is less reliable than the tables for other nutrients.
Buying selenium: more µg is not a better deal
With selenium the gap between requirement and upper level is small. Why the high dose is no advantage and which four items must appear on every label.
Selenium forms: selenite, selenomethionine or yeast?
Six selenium sources are permitted in the EU. What the form really changes in the body — and why a higher blood selenium level is not automatically better supply.
Taking selenium: timing, meals, vitamin C
The well-known gap to vitamin C applies to only one kind of selenium supplement — and even there the evidence is mixed. What timing really changes.
Melatonin: the right time to take it in the evening
"Close to bedtime" — but how close? Where the one-to-two-hour rule comes from, why it does not apply to every tablet, and what food changes.
Melatonin: spray or tablet?
A spray reaches the blood faster, a tablet states more precisely how much is in it. What the evidence shows and what matters when buying.
Melatonin for children and teenagers: the rules
For children, melatonin is only available on prescription in the EU. What food supplements may do, what the BfR advises and why teenagers get tired later.
Melatonin for jet lag: direction, timing, amount
The authorised claim is tied to at least 0.5 mg close to bedtime at the destination. Why the direction of the flight decides and when the timing goes wrong.
Is melatonin addictive? What the evidence shows
Tolerance, dependence, rebound: what long-term studies on melatonin actually show, where the data is thin and which kind of habituation really exists.
Melatonin dosage: 0.5, 1, 2, 5 or 10 mg?
The authorised claim is tied to 1 mg per portion, the jet lag claim to 0.5 mg. What higher strengths mean and where medicines law begins.
Too much magnesium: reading the 250 mg limit
250 mg maximum in a supplement, 375 mg NRV: why the two figures do not contradict each other and what actually happens with too much magnesium.
Taking magnesium: morning, evening or split?
Is there a best time of day for magnesium? What actually counts: portion size, regularity and the gap to certain medicines.
Magnesium and vitamin D: what connects them
Magnesium is said to "activate" vitamin D: where that sentence comes from, what the studies actually show and which claims are authorised for the two.
Magnesium and calcium: reading the 2:1 ratio
Where the 2:1 ratio of calcium to magnesium comes from, why it is not a dosing rule, and whether the two minerals have to be taken separately.
Magnesium daily requirement: 375, 350 or 250 mg?
375 mg NRV, 350 or 300 mg estimated value, 250 mg maximum in a supplement: which figure applies to what, and how much of it the diet already covers.
Magnesium and exercise: what sweat actually costs
How much magnesium is really lost in sweat during exercise, what the authorised claims cover and what the data actually say about muscle cramps.
Magnesium and sleep: what may be claimed
No sleep claim is authorised for magnesium. What the studies actually show, which claim melatonin carries and how to read a combination product.
Magnesium in food: table & realistic portions
Pumpkin seeds top every magnesium table, yet people eat 15 g of them. Which foods actually deliver the most per realistic portion – with two tables.
Buying magnesium: compare the price per mg properly
The pack price says little. How to work out the price per 100 mg of elemental magnesium, what a label has to state and which additives are usual.
Magnesium forms compared: bisglycinate, citrate & co.
Magnesium bisglycinate, citrate, oxide and malate: how the forms differ chemically, what elemental content means and how to read a label properly.
Vitamin D3 dosage: 1000 IU to 10000 IU – what makes sense?
How much vitamin D per day makes sense? Compare dosages from 1000 IU to 10000 IU, daily versus weekly intake and depot effects.
Melatonin duration: how long does it act in the body?
How long does melatonin last? Half-life, how the body clears it and how to avoid feeling groggy the next morning.
Melatonin, valerian and ashwagandha compared
Melatonin, valerian and ashwagandha compared: origin, use and differences between the three substances, set out factually.
Melatonin and shift work: a guide to taking it
Melatonin 10 mg and shift work: guidance on how, when and how much to take for daytime sleep after a night shift.
Vitamin D3 K2 20,000 IU: the high dose compared
High-dose vitamin D3/K2 (20,000 IU): how it differs from lower dosages and what to bear in mind when taking it.
Why shouldn't you take alcohol and melatonin together?
Alcohol and melatonin together? Why this combination disrupts sleep, what the risks are and what to watch out for — clearly explained.
Taking vitamin D3 K2 5000 IU correctly: a guide
Vitamin D3 and K2 (5000 IU): guidance on intake, timing and combining these two fat-soluble vitamins, summarised factually.
The Impact of Vitamin D3 and Alcohol Interaction on Health
The Impact of Vitamin D3 and Alcohol Interaction on HealthIntroductionWelcome, dear readers. Health is our most valuable asset, and the daily decisions we make have an enormous influence on it. In par
Ashwagandha and ginseng compared: the differences
Ashwagandha and ginseng compared: origin, botanical characteristics and traditional use of the two plants, set out factually.
Ashwagandha recipes: simple ideas for everyday life
Ashwagandha (Withania somnifera) in the kitchen: simple recipe ideas and tips for working the Ayurvedic powder into everyday life without fuss.
Ashwagandha side effects: the possible risks at a glance
Ashwagandha (Withania somnifera): the plant's origin, use in Ayurveda plus possible side effects and interactions, in a factual overview.
Ashwagandha for students: what to know about the Ayurvedic root
Ashwagandha (Withania somnifera): origin, Ayurvedic tradition and background on the root — an overview for student life.
Ashwagandha for skin: traditional use at a glance
Ashwagandha in skincare: origin, traditional use in Ayurveda and a simple do-it-yourself recipe, at a glance.
Can you take too much vitamin D?
Can vitamin D be overdosed? What counts as too much, where the normal range lies and what to watch for at higher dosages.
Vitamin K2 and calcium: the combination at a glance
Taking vitamin K2, D3 and calcium together: what to watch for in this combination and which interactions are possible — explained factually.
Vitamin K2 overdose: what you should know
Overdosing vitamin K2 and D3: what counts as too much, the role of the recommended amount and what to watch for when taking them.
5-HTP: what to know about taking it
5-HTP (300 mg): background on the origin, use and intake of this amino acid precursor — summarised factually.
Can you take vitamin D3 on an empty stomach?
Vitamin D3 on an empty stomach or with a meal? Guidance on the best time to take this fat-soluble vitamin, summarised factually.