Published 20 October 2026 · Last updated 20 October 2026
High Strength · Adults · One Tub, Any Frequency
Is 5000 IU Of Vitamin D Too Much? Only If You Take It Wrong
The daily ceiling for adults is 100 micrograms. Our tablet holds 125. Almost everyone reads that and assumes it rules the product out — but the ceiling is a daily average, and that one word changes everything. Here is the arithmetic, and why a high-strength tablet is the most flexible vitamin D you can own.
The Short Answer
Space it and you are comfortably inside every published limit. One 5000 IU tablet every other day averages 62 micrograms a day. Twice a week averages 36. The adult ceiling is 100. Both sit well under it, and neither requires you to cut a tablet in half.
That is the whole point of buying high strength. A 10 microgram tablet can only ever give you 10 micrograms. A 125 microgram tablet can give you anything from 18 to 125 a day depending on how often you take it — so one tub covers the dark months, the light months, and whatever a blood test tells you to do next.
Vitamin D is the one supplement where British geography does the arguing for you. Between roughly October and March there is not enough UVB in the sunlight at this latitude for skin to make any vitamin D at all, however long you stand outside. The NHS advice reflects that directly: it recommends a daily supplement "during the autumn and winter months".
Which raises the obvious question that almost no supplement page answers. If the need is seasonal, why would you buy a product that can only do one dose?
The spacing table — this is the useful bit
One tablet holds 125 micrograms (5,000 IU). Here is what that becomes as a daily average at different frequencies, and how long a 365-tablet tub lasts at each.
| How often | Daily average | Inside the 100 µg ceiling? | 365 tub lasts |
| Once a week | 18 µg | Yes — 18% | 7 years |
| Twice a week | 36 µg | Yes — 36% | 3 years 6 months |
| Three times a week | 54 µg | Yes — 54% | 2 years 4 months |
| Every other day | 62 µg | Yes — 62% | 2 years |
| Five days a week | 89 µg | Yes — 89% | 1 year 5 months |
| Every day | 125 µg | Above it, by 25% | 1 year |
Five of those six rows sit inside the ceiling, most of them with a great deal of room. Every other day is the one most of our customers settle on — it is easy to remember, it lands at 62 micrograms a day, and it turns a single 365 tub into a two-year supply. Our pack directions are one tablet daily as a maximum; where you sit below that is your choice to make, and this is the table to make it from.
Our label says one tablet daily maximum. It has never said one tablet daily minimum, and the table above is why.
A word on the frightening number on the label
Our pack says 2,500% NRV. The 10,000 IU tablet says 5,000% NRV. These are the figures that make people put the tub back down, so here is what they actually mean.
The NRV — Nutrient Reference Value — for vitamin D is 5 micrograms. That is the figure every supplement in the country must calculate its percentage against, because it is fixed in labelling law. So 125 µg divided by 5 µg is 25, and the label has to print 2,500%. It is arithmetic, not a warning.
Now notice something odd. The NRV is 5 µg, but the UK's own Reference Nutrient Intake is 10 µg — the figure the NHS advice is built on. The value used for labelling is half what the UK actually recommends you get. Two numbers, set by two different processes for two different purposes, and nothing on a pack explains it.
So the percentage on any vitamin D label overstates the size of the dose by a factor of two before you start. Ignore the percentage and work in micrograms against the 100 µg ceiling — that is the comparison that means something. It is why this page is written in micrograms throughout.
Why Spacing Works For This Vitamin And Not Others
Vitamin D is fat-soluble. The body holds a reserve of it in fat and liver tissue and draws on that reserve between doses, which is exactly why you can get through a British winter on a summer's worth of sunshine at all.
That is the opposite of vitamin C or the B vitamins, which are water-soluble, are not stored, and genuinely do need topping up daily. Intake guidance for vitamin D is expressed as a daily average for this reason — the storage smooths it out. It is why intermittent dosing is a normal, well-understood way to take it, and why the same approach would make no sense for a B-complex.
The seasonal case — the real reason to own high strength
Here is the thing a fixed-dose tablet simply cannot do.
The NHS recommends supplementing in autumn and winter for the general adult population, and extends it to all year round for people who are not often outdoors, people in care homes, people who cover most of their skin outside, and people with dark skin. In other words the official advice itself varies by season and by person — and most people's circumstances change across a year.
One tub of a high-strength tablet handles all of it:
October to March. The dark half of the year, no skin synthesis. Run it more often — every other day, or three times a week.
April to September. Long days, short sleeves, skin making its own. Ease back to once or twice a week, or stop.
A desk job and a dark winter. Hold the higher frequency year-round, still inside the ceiling.
A blood test comes back and changes the picture. You already own the right product. You just change how often you open the tub.
A 10 microgram tablet can do precisely one of those four things. It has no headroom, because the dose is fixed at the bottom of the range. Buying high strength and spacing it is the only way to own a single product that covers every one of them — and it is why we build the range high rather than low.
Why anyone sensible looks past 10 micrograms
Ten micrograms is the UK Reference Nutrient Intake — the figure set to cover the requirements of the great majority of the population. It is a maintenance number. It describes what keeps a person who is already in good standing in good standing.
The problem is that the national survey data says a great many people are not in that position to start with. The National Diet and Nutrition Survey is the government's rolling programme measuring what the UK actually eats and what turns up in people's blood:
| What NDNS found | Figure |
| Adults aged 19–64 with low vitamin D status in the blood | 16% |
| Adults aged 65 and over with low vitamin D status | 13% |
| Young people aged 11–18 with low vitamin D status | 19% |
| Vitamin D intake from food alone, against the 10 µg RNI | A quarter to a third |
| Intake for adults 19–64 including supplements, against the RNI | 54% |
| Adults 19–64 taking any vitamin D supplement at all | 17% |
Read the last two rows together. Even counting everyone's supplements, the average adult sits at roughly half the recommended intake — and the reason is that only about one adult in six takes anything. Food alone gets nobody there; the richest everyday sources are oily fish and egg yolk, and British diets do not contain enough of either.
That is the honest case for having headroom in the product you buy. A tablet that tops out at 10 micrograms assumes you are starting from par. A lot of people are not, and the only way to know which you are is a blood test — which is the single most useful thing anyone reading this can do.
Where the 100 microgram figure comes from
Worth understanding properly, because three separate bodies arrive at the same number by different routes — and none of them is a law.
The NHS
Plain wording: "Do not take more than 100 micrograms (4,000 IU) of vitamin D a day as it could be harmful." Applied to adults, including pregnant and breastfeeding women and older adults, and to children aged 11 to 17.
EFSA
The European Food Safety Authority sets a Tolerable Upper Intake Level — the highest long-term daily average intake judged unlikely to cause harm — of 100 micrograms for adults. A UL is a safety assessment, not a target. There is no prize for getting closer to it.
The UK supplement industry itself
Three trade associations — CRN UK, the HFMA and PAGB — jointly publish a voluntary maximum level for vitamin D in food supplements, raised in 2023 from 75 micrograms to 100. A figure the industry agreed among itself, landing in the same place as the other two.
The Distinction Most People Get Wrong
There is no legal maximum for vitamin D in UK food supplements. The law governs which chemical forms may be used and how a product must be labelled. It does not cap the dose. That is why 5000 IU and 10,000 IU tablets are sold openly and entirely lawfully right across the UK.
So anyone telling you a 5000 IU tablet is illegal is simply wrong. And anyone quoting the 100 microgram figure as a per-tablet limit has misread it — it is a daily average, which is exactly why the spacing table at the top of this page works.
Why this is an adults-only product
Both our vitamin D tablets are high strength, and the ceilings for children are considerably lower. The NHS figures:
| Age | NHS daily maximum |
| Under 12 months | 25 µg (1,000 IU) |
| 1 to 10 years | 50 µg (2,000 IU) |
| 11 to 17 years | 100 µg (4,000 IU) |
| Adults, including pregnancy and breastfeeding | 100 µg (4,000 IU) |
Children's vitamin D is sold as drops and low-dose chewables for exactly this reason, and that is the right product for them. Everything on this page is written for adults, and our label says adults only. The spacing approach above is not a route to giving a high-strength adult tablet to a child — don't.
Safety — Please Read
Do not stack it. This is far and away the commonest way people end up well over the ceiling, and it is always an accident — a high-strength D3 plus a multivitamin plus a cod liver oil capsule, each perfectly sensible on its own. Add up every vitamin D source you take, not just this one. If you take a multivitamin, check it before you start.
Because vitamin D is stored rather than cleared, very high intakes accumulate over months. The NHS states that taking too much over a long period "can cause too much calcium to build up in the body (hypercalcaemia)", which "can weaken the bones and damage the kidneys and the heart." That is a long-term, high-intake effect — not a risk of the spacing described above, which stays inside the ceiling.
Vitamin K2 and anticoagulants. Vitamin K is directly involved in blood clotting, which is the mechanism warfarin and similar drugs act on. If you take an anticoagulant, speak to your doctor or pharmacist before taking any vitamin K supplement.
You cannot get too much vitamin D from sunlight — the NHS is explicit about that. The risk here comes from supplements only. Not recommended in pregnancy or breastfeeding without medical advice. If in any doubt, ask your GP or pharmacist, and ask for a blood test.
What vitamin D and K2 are authorised to say
Unlike most of what we sell, these two vitamins carry authorised health claims on the Great Britain Nutrition and Health Claims Register. There are only around 220 authorised claims in total across every ingredient in existence — and vitamins D and K hold nine of them between them. That is unusually strong ground. The wording is fixed, and we are not allowed to improve on it:
Vitamin D — Seven Authorised Claims
Vitamin D contributes to normal absorption/utilisation of calcium and phosphorus
Vitamin D contributes to normal blood calcium levels
Vitamin D contributes to the maintenance of normal bones
Vitamin D contributes to the maintenance of normal muscle function
Vitamin D contributes to the maintenance of normal teeth
Vitamin D contributes to the normal function of the immune system
Vitamin D has a role in the process of cell division
Vitamin K — Two Authorised Claims
Vitamin K contributes to normal blood clotting
Vitamin K contributes to the maintenance of normal bones
What each of those means in plain terms:
Calcium and phosphorus absorption, and normal blood calcium levels
These two are the foundation the rest sit on. Vitamin D is the nutrient involved in how the gut takes calcium and phosphorus out of food and into the bloodstream, and in how the body holds blood calcium steady. Calcium in the diet is only useful once it has been absorbed, and vitamin D is part of that step.
Maintenance of normal bones, and of normal teeth
Bone and tooth structure is built largely from calcium phosphate, and both are living tissue that is continually renewed rather than finished and left alone. Vitamin D contributes to maintaining them — which follows from the absorption role above. Vitamin K independently carries the same bone claim, which is the straightforward reason the two are so often sold together.
Maintenance of normal muscle function
Muscle contraction is a calcium-signalled process, and vitamin D contributes to maintaining normal muscle function. This is one of the claims people are least aware exists, and it is fully authorised.
Normal function of the immune system
Vitamin D contributes to the immune system working normally. Given that the months when skin makes no vitamin D in Britain are also the months people are indoors together, this is the claim most winter buyers have in mind.
A role in the process of cell division
Cell division is the basic process of tissue renewal and repair, going on constantly throughout the body. Vitamin D has an authorised role in it.
Normal blood clotting
Vitamin K is the vitamin involved in the clotting process — the K comes from Koagulation. That is also precisely why the anticoagulant warning above matters.
Now the part usually left out. There is no authorised claim for vitamin D and vitamin K2 working together, and no authorised heart or cardiovascular claim for either of them. The combination is extremely common and the reasoning behind it is widely discussed, but none of it has been through authorisation, so you will not find it stated as fact on our pages. The two are in one tablet here because most people buying either want both, and nine authorised claims in one tablet is a better proposition than two bottles.
Our Tablet, Declared In Full
Vitamin D3 5000 IU & K2 MK-7 100 µg
| Vitamin D3 | 125 µg (5,000 IU) — 2,500% NRV |
| Vitamin K2 | 100 µg as menaquinone-7 (MK-7) — 133% NRV |
| Form of D3 | Cholecalciferol, on an acacia gum and starch carrier |
| Tablet | 8mm, uncoated, neutral — easy to swallow |
| Pack sizes | 120, 200, 365, 500 and 1,000 tablets |
| Suitable for vegetarians | Yes |
| Suitable for vegans | No — the cholecalciferol is not lichen-derived |
| Contains | Sucrose, in the D3 preparation. Binders: microcrystalline cellulose and dicalcium phosphate |
| Made | In house, Southend-on-Sea. 5 Star Food Hygiene Rating |
| Certificate | Per batch, free on request — just send us the batch number |
Two of those rows cost us sales and both stay. We are not a vegan product, and the vitamins are supplied as standardised preparations on carriers, because that is how fat-soluble vitamins are made into a tablet at all. You will find the full declaration on the pack as well as here.
▸ Vitamin D3 5000 IU & K2 MK-7 100 µg Tablets — from 120 to 1,000 tablets
▸ Or the 365-tablet pack on our eBay shop — a two-year supply at every other day
The other tablet: D3 10,000 IU, no K2
We make a second vitamin D tablet, and it exists for two quite different reasons. It holds 10,000 IU — 250 micrograms of cholecalciferol, 5,000% NRV — and nothing else. No K2, nothing alongside it.
Everything on this page applies to it. The arithmetic is identical; only the numbers move. Because each tablet is double the 5000 IU, the spacing has to be wider:
| 10,000 IU tablet — how often | Daily average | Inside 100 µg? | 365 tub lasts |
| Once a week | 36 µg | Yes — 36% | 7 years |
| Twice a week | 71 µg | Yes — 71% | 3 years 6 months |
| Three times a week | 107 µg | Above it | 2 years 4 months |
| Every day | 250 µg | Above it, by 150% | 1 year |
The directions on that one are the same as ours always are — one tablet daily, do not exceed the recommended dose — and at 250 micrograms that sits above the 100 microgram figure, which the product page states plainly. If you would rather place yourself inside it, twice a week comes to 71 micrograms a day and once a week to 36. Three times a week already puts you over. It is a tablet to use deliberately rather than casually, whichever frequency you settle on.
So why would you choose it over the 5000 IU?
You want D3 without any vitamin K. This is the important one. Vitamin K is involved in blood clotting, which is the mechanism anticoagulants such as warfarin act on — so people on those medicines are generally advised to keep vitamin K intake steady rather than add to it. If you need vitamin D but have been told to be careful with vitamin K, a D3-only tablet is the one that makes sense. Speak to your doctor or pharmacist first either way.
You already take K2 separately. Plenty of people do, often at a different strength than ours. No sense paying for it twice.
You want the fewest tablets possible. Twice a week, for three and a half years, from one tub. It is about as low-maintenance as supplementing gets.
And when you would not: if you want something you can take most days, the 5000 IU with K2 is the better of the two, because it has room to be taken often. That is the honest split between them — 5000 IU for frequency and flexibility, 10,000 IU for fewest tablets and no vitamin K.
▸ Vitamin D3 10,000 IU Tablets — 250 µg cholecalciferol, 5,000% NRV
Setting your own frequency
Four steps, in order.
1. Add up what you already take. Multivitamin, cod liver oil, fortified spread, any separate D3. All of it counts toward the same ceiling, and people are often further along than they realise.
2. Pick a frequency off the table and stick to it. Every other day is the common choice: simple to remember, 62 micrograms a day, two years from a 365 tub. Take it with a meal containing some fat — vitamin D is fat-soluble and absorbs better that way.
3. Adjust for the season if you want to. More often October to March, less often or not at all April to September. This is the flexibility you bought the product for — use it.
4. Get tested if you want to stop guessing. A serum 25(OH)D result turns this from a judgement into arithmetic. Your GP can arrange it and private tests are widely available. If a clinician gives you a dose, theirs is the instruction to follow — not a label, and not this page.
Questions
So is 5000 IU too much or not?
Taken every single day, long term, it is 25% above the adult ceiling. Taken every other day it is 62 micrograms a day, comfortably inside it. The number on the tablet is not the number that matters — your daily average is, and you control that by how often you take it.
Is it legal to sell a 5000 IU tablet in the UK?
Yes. UK food supplement law sets out which forms of vitamins may be used and how they must be labelled, but sets no maximum dose for vitamin D. The 100 microgram figure comes from NHS advice, the EFSA upper intake level and a voluntary industry maximum — all advisory rather than statutory.
Why not just buy a 10 microgram tablet?
You can, and if you want one fixed low dose forever it will do the job. What it cannot do is move. It has no headroom for a dark winter, for a low blood test result, or for the year-round groups the NHS flags — and it tops out at the maintenance figure. A 125 microgram tablet covers that whole range from one tub, and includes the K2.
Won't I forget which days I'm meant to take it?
Every other day is the easiest to hold on to, and a pill box or a phone reminder settles it. Twice a week works well if you peg it to fixed days. Because vitamin D is stored rather than cleared, missing one is not a problem you need to correct for — just carry on with the next one, and don't double up.
What does the K2 do in it?
On its own account, vitamin K holds two authorised claims: it contributes to normal blood clotting and to the maintenance of normal bones. What we are not permitted to tell you, and will not imply, is anything about the two vitamins acting together — no such claim has been authorised.
Why MK-7 rather than MK-4?
MK-7 is the long-chain menaquinone used in most K2 supplements and is the form in ours, at 100 micrograms — 133% of the NRV. The authorised claims apply to vitamin K generally rather than to one particular menaquinone.
Is it vegan?
No. It is suitable for vegetarians, but the cholecalciferol is not lichen-derived, so we do not describe it as vegan. If that matters to you, buy a stated lichen-source D3 from someone who makes one.
Can I take it in pregnancy?
The NHS applies the same 100 microgram ceiling in pregnancy and breastfeeding, and we do not recommend this tablet in either without medical advice. The NHS does recommend a 10 microgram daily supplement throughout pregnancy — a different and much smaller product. Speak to your midwife or GP.
Which pack size should I get?
Work from your frequency, not from the headline count. At every other day, 120 tablets is eight months, 365 is two years and 500 is nearly three. Larger packs are cheaper per tablet, so match the pack to what you will actually finish rather than buying the biggest one.
Will a certificate come with it?
Free on request for any batch, as with everything we sell. Email us the batch number from the tub.
Sources
Every figure above is checkable. These are the pages they come from.
▸ NHS, Vitamin D — the 10 microgram advice, the 100 microgram maximum, the children's limits and the hypercalcaemia wording: nhs.uk/conditions/vitamins-and-minerals/vitamin-d
▸ National Diet and Nutrition Survey — the low-status percentages, the intake-against-RNI figures and the supplement-taking figure: gov.uk — National Diet and Nutrition Survey
▸ CRN UK, HFMA and PAGB tripartite briefing (November 2023) — the voluntary UK industry maximum of 100 µg, raised from 75 µg: crnuk.org — Tripartite briefing paper
▸ SACN, Vitamin D and Health (2016) — the report behind the 10 microgram UK Reference Nutrient Intake: gov.uk — SACN Vitamin D and Health report
▸ GB Nutrition and Health Claims Register — the authorised wording for all nine vitamin D and vitamin K claims: gov.uk — GB NHC Register
▸ Food supplements legislation guidance — on what UK law does and does not regulate: gov.uk — Food supplements guidance and FAQs
Vitamin D status surveillance is updated periodically, and the NDNS figures above come from the most recently published rounds. Where a newer round has moved a number, the direction of the finding has been consistent across every round so far.
This article is general information about vitamin D dosing and UK guidance. It is not medical advice and is not a substitute for it. If you are unsure how much vitamin D to take, or you take any prescribed medicine, speak to your GP or pharmacist. Only the nine authorised claims quoted above are made; the plain-language explanations alongside them describe how the nutrient is involved and are not additional claims. No claim is made for vitamin D and vitamin K2 in combination.
Food supplement. Not a medicine. Not a substitute for a varied and balanced diet or a healthy lifestyle. Do not exceed one tablet daily. Do not take alongside other vitamin D supplements or multivitamins containing vitamin D. Adults 18 and over only — not suitable for children. Keep out of reach of children. Not recommended during pregnancy or breastfeeding without medical advice. Speak to your doctor before use if you take an anticoagulant such as warfarin, or if you have a condition affecting blood calcium or kidney function. Store sealed in a cool, dry place away from direct sunlight.
Charge Products is a trading name of Big Idea Services Ltd, Company No. 11645389. Unit 1, 8 Towerfield Road, Southend-on-Sea, Essex SS3 9QE. 5 Star Food Hygiene Rating. Last updated: October 2026.
