Vitamin D is the nutrient behind calcium absorption, and it supports bone strength, muscle and immune function. Australia's recommended dietary intake is 5 micrograms a day for adults aged 19 to 50, rising to 15 micrograms past 70, and our formula carries 25 micrograms of vitamin D3 per 10 g serve, listed on the public register as AUST L 508472 (published 8 August 2025). That's 1,000 IU. It travels with 50 micrograms of vitamin K2, because vitamin D supports calcium absorption and vitamin K2 supports bone and cardiovascular health.
TL;DR
- Vitamin D's strongest evidence is calcium handling and bone support. The wider claims are still being tested.
- The daily intake references are modest: 5 micrograms for Australian adults aged 19 to 50, 10 micrograms from 51 to 70, 15 micrograms past 70, and 15 to 20 micrograms (600 to 800 IU) in the US RDA.
- Our figure is 25 micrograms (1,000 IU) per 10 g serve. That's above the intake references and a long way below the 100 microgram (4,000 IU) tolerable upper intake level for adults.
- Vitamin K2 sits in the formula at 50 micrograms per serve because the two nutrients work the same mineral from different sides. Menaquinone-7 is the K2 form we use.
- The D3 itself is Vitashine, a vegan form. Supplement D3 is typically produced from lanolin, the fat in sheep's wool.
- Every number is checkable. Search 508472 on the TGA's public register and the entry comes up under Hoola Australia Pty Ltd.
What does vitamin D actually do?
Vitamin D's main job is calcium. It promotes calcium absorption in the gut, and it helps keep calcium and phosphate at the levels bone needs to rebuild itself.
The NHS keeps its own description just as short: vitamin D helps regulate the amount of calcium and phosphate in the body, and those nutrients are what keep bones, teeth and muscles healthy. Healthdirect Australia adds the wider list, noting that vitamin D matters for the immune system, skin, muscles and brain, and that it helps control the amount of calcium in the blood.
It's worth separating what's well supported from what isn't. Harvard Health's read is that support for vitamin D's role in bone health is strong, while the evidence that it does more than that is not conclusive yet. Keep that gap in mind when you read the louder claims about the vitamin.
Our own wording stays inside it. Vitamin D3 is in Hoola to support calcium absorption, bone strength, muscle and immune function. Note the verb: support is the language a listed product uses for an ingredient's role, and it's as far as we take it.
How much vitamin D do you need each day?
The reference numbers for adults are small, and they depend on your age and on which country's framework you're reading.
Australia's recommended dietary intake is 5 micrograms a day for adults aged 19 to 50, 10 micrograms from 51 to 70, and 15 micrograms past 70. The United States sets its Recommended Dietary Allowance higher: 15 micrograms (600 IU) for adults up to 70 and 20 micrograms (800 IU) past that, working on the assumption that sun exposure is minimal.
| Age | Australia (RDI) | United States (RDA) |
|---|---|---|
| 19 to 50 | 5 mcg | 15 mcg (600 IU) |
| 51 to 70 | 10 mcg | 15 mcg (600 IU) |
| Over 70 | 15 mcg | 20 mcg (800 IU) |
Those two figures do different jobs. The Australian number is the amount to aim for from food; the US number assumes almost no sun. Neither is a supplement dose, and neither is a ceiling.
The ceiling, in reference terms, is the tolerable upper intake level: 100 micrograms (4,000 IU) a day for adults. So where does our 25 micrograms sit? Above the intake references, and a quarter of the way to that upper level. Position on a scale is all it is. The number tells you what's in the scoop, not what it will do for you. No dose answers that on its own.
Most Australians meet their vitamin D needs from the sun rather than the fridge. Healthdirect's guidance is that a few minutes outdoors on most days covers summer, while winter in the southern states calls for time outside in the middle of the day with enough skin exposed.
Food is the harder route. Healthdirect states it plainly: it's almost impossible to get enough vitamin D from food alone. The numbers show why.
| Food (per 100 g) | Vitamin D3 equivalents (mcg) |
|---|---|
| Mushrooms, exposed to UV light | 24.18 |
| Anchovy | 12.38 |
| Margarine | 12.09 |
| Chicken | 6.9 |
| Salmon | 6.21 |
| Egg | 5.78 |
Salmon is one of the better sources on that list, at about 6.2 micrograms per 100 grams. Getting 25 micrograms from salmon alone means roughly 400 grams of fish in a day.
Ours comes in a scoop instead, and the figure is 25 micrograms (1,000 IU) per 10 g serve of the Hoola Daily Multivitamin. The rest of the panel is broken down in the full ingredient breakdown if you want to see what sits alongside it.
Why does vitamin K2 travel with vitamin D3?
Because calcium needs both an entry point and a destination. Vitamin D supports calcium absorption, while vitamin K is a cofactor for several proteins, including ones involved in bone metabolism.
Two of those proteins get most of the attention. Osteocalcin is one of the main proteins in bone, and vitamin K is needed for its carboxylation. Matrix Gla-protein sits in blood vessel walls and is studied for its part in how calcium deposits form there.
That's the logic of the pairing, and it's why the two lines sit next to each other on a panel. Our K2 entry states what it's there for: supports bone and cardiovascular health.
The detail is still being worked out, and the ODS says so. Its assessment is that the role of the different vitamin K forms in cardiovascular research is unclear and remains an active area of study. Nutrition science rarely closes a question all the way, which is why our panel uses support rather than anything stronger. There's more on the K2 side in our explainer on what vitamin K2 does in the body.
What is menaquinone-7?
Menaquinone-7, written MK-7 on most labels, is one member of the vitamin K2 family.
Vitamin K comes in two main forms: phylloquinone, or K1, which is the kind in leafy greens, and a series of menaquinones, or K2, which are named MK-4 through MK-13 according to the length of their side chains. MK-4, MK-7 and MK-9 are the most studied of them, and supplements generally use K2 as MK-4 or MK-7.
K2 turns up in fermented and animal foods. Natto, fermented soybeans, is the standout, carrying around 850 micrograms per three-ounce serve as MK-7.
We use menaquinone-7 at 50 micrograms per 10 g serve. On the register entry it reads as 5 micrograms per gram. One label quirk while you're here: both K vitamins in the formula appear under their chemical names. Phytomenadione is vitamin K1, and menaquinone 7 is vitamin K2.
Does it matter whether the vitamin D is D3 or D2?
A little, and in D3's direction. Both forms raise the level the body measures, but most evidence indicates that D3 lifts it further and holds it there for longer.
The two also start in different places. D2 is made from plant material, typically by treating yeast with UV light, while D3 is typically produced from lanolin, the fat in sheep's wool. Your skin makes its own D3 when you're in the sun, which is where the sunshine vitamin nickname comes from.
Hoola uses the D3 form. On the register it's named colecalciferol.
Where does Hoola's vitamin D3 come from?
From Vitashine, a vegan vitamin D3.
That's worth a sentence because of where D3 usually starts. The ODS describes the standard production route: D3 is typically made by irradiating a compound extracted from lanolin, the fat in sheep's wool. The plant-side option, D2, skips that input, but the measured level doesn't rise as far or hold as long.
If you avoid animal products, that's a detail worth checking on any panel, and ours is the vegan form. The rest of the label follows the same line: vegan, no sugar, gluten free, no artificial fillers.
How do you check a product's vitamin D on the register?
Find the AUST L number, then search it on the TGA's public register at tga.gov.au/resources/artg. The entry that comes back is the claim-free version of the label.
We ran that search ourselves. Searching 508472 returns HOOLA (508472), published 8 August 2025, sponsored by Hoola Australia Pty Ltd. The listing sets out all 27 actives and their quantities per gram, which is where our 25 micrograms of vitamin D3 comes from.
Three things are worth checking on any product once you're there:
- The amount per serve, not just per gram. Our 2.5 micrograms per gram becomes 25 micrograms in the 10 g scoop.
- The unit. Micrograms and IU are two rulers for the same vitamin, and one microgram is 40 IU.
- The form, because register entries use chemical names. Colecalciferol is vitamin D3, ergocalciferol is D2, and menaquinone 7 is the K2 form.
If you don't have the number in front of you, the same search page takes a product or sponsor name.
Every figure for the formula sits on that register entry, and all 27 actives are published with the Hoola Daily Multivitamin. The 150 g pouch covers 15 days at $65, and subscription brings it to $99 a month with the welcome pack. Shop by ingredient with the vitamin D3 and vitamin K2 ranges. Turn up the brightness.
Frequently asked questions
What does vitamin D help with most?
Calcium absorption, and the bone maintenance that follows from it. Healthline's summary of the vitamin's core role is the plainest one: it helps the body absorb and retain calcium and phosphorus, which is what keeps bones strong. Everything else vitamin D gets credit for sits further from the centre of the evidence.
Can you get enough vitamin D from food?
Not realistically. Healthdirect's line is that it's almost impossible to get enough vitamin D from food alone, and the food table above shows why: the best source on it tops out around 24 micrograms per 100 grams. Sun exposure does the heavy lifting for most Australians, and fortified foods such as margarine add a little to the total.
Does your skin still make vitamin D in winter?
In southern Australia, yes, if you get the timing right. Winter production works when you're outside in the middle of the day with enough skin exposed, while summer asks for far less time than most people expect.
Is 1,000 IU of vitamin D a lot?
Against the reference numbers, no. The tolerable upper intake level for adults is 100 micrograms, or 4,000 IU, so 1,000 IU is a quarter of the way to it, and the daily intake references sit lower again at 5 to 20 micrograms depending on your age and which country's framework you read.
What's the difference between micrograms and IU?
Same vitamin, two units, and the conversion is simple: one microgram of vitamin D equals 40 IU. So 10 micrograms is 400 IU, and 25 micrograms is 1,000 IU. Both describe the same amount of the same vitamin.
Does vitamin D need fat to be absorbed?
Yes. Vitamin D is fat soluble, so how much you absorb depends on your gut's ability to absorb dietary fat. It's also the reason the vitamin can be stored in the body rather than passed straight through.
