Most vitamin D supplements stop at D3. This one pairs it with K2, the vitamin that helps direct calcium to your bones, in a single daily drop.

At a glance

What it is: A liquid vitamin D3 and K2 supplement. D3 helps your body absorb calcium. K2 helps direct that calcium to your bones.

What’s in a drop: 600 IU vegan vitamin D3 (100% RDA) and 20 mcg vitamin K2 as MK-7, in coconut MCT oil.

How to take it: 1 drop a day, or the dose your practitioner advises based on your vitamin D levels. Under the tongue or in any drink, ideally with a meal. One 20ml bottle holds about 600 drops.

Vegan. D3 from lichen, not fish oil or sheep’s wool.

Check with your practitioner first if you:

take blood thinners such as warfarin
are pregnant or breastfeeding

Storage: Cool, dry place away from sunlight. Do not refrigerate. Use within 12 months of opening.

Why this formula is different

D3 with K2, not D3 on its own

D3 gets calcium into your bloodstream. K2 is what helps send it to your bones. Taking the two together means the job gets finished.

The science: how D3 and K2 work together ▾

Most Vitamin D supplements are incomplete.

Vitamin D3 drives calcium absorption from your gut into your bloodstream. But once calcium is in circulation, it needs direction. Without Vitamin K2, absorbed calcium has no clear destination. K2 activates two proteins namely osteocalcin and MGP (Matrix Gla Protein) that direct calcium into bone matrix. D3 without K2 is a half-solution.

iThrive Vitamin D3 + K2 in MCT Oil delivers both in a single liquid drop. In a fat-soluble MCT oil base because D3 and K2 are fat-soluble vitamins that require fat for absorption. Stabilised with natural Vitamin E to protect potency during storage. No synthetic emulsifiers. No unnecessary additives.

K2 that is verified to be the active form

K2 comes in an active form and less active look-alikes, and most labels don’t tell you which you’re getting. The K2 in this bottle is tested to be 100% the active form.

The science: the cis isomer problem ▾

The cis isomer problem and why most buyers don’t know about it:

Vitamin K2 as MK-7 exists in two structural forms: all-trans MK-7 (the biologically active form found naturally in natto) and cis isomers (forms with altered spatial geometry that have significantly reduced biological activity compared to the trans form).

The all-trans form is linear in structure and its extended isoprenoid side chain allows it to associate with the subcellular enzymes that activate osteocalcin and MGP. The cis isomers are non-linear. Their bent molecular shape compromises their ability to activate these proteins, resulting in negligible carboxylative capacity compared to all-trans MK-7.

What independent academic analysis found in the supplement market:

Peer-reviewed research (Szterk et al., ScienceDirect, 2017/2018) analysed MK-7 supplements and found that in the majority of products tested, the actual all-trans MK-7 content was lower than what the label declared. In some products, cis isomer content exceeded all-trans MK-7 by up to 3.7 times. In one product, no all-trans MK-7 was found at all despite the label claim. These are commercially available supplements, tested independently.

This happens because the US Pharmacopeia standard for MK-7 ingredients requires only 96% all-trans MK-7, allowing up to 4% cis isomer content in an ingredient before it fails quality standards. And finished supplement products are not required to test cis vs trans content at all, meaning low-quality MK-7 can enter products without disclosure.

Pharmaquinone®: why we chose it:

Pharmaquinone®, produced by Vitasynth (Poland), is validated as containing no cis isomer according to Vitasynth’s own testing per the US Pharmacopeia method, the recognised international standard for MK-7 ingredient purity. Supply availability and sourcing consistency at the volumes we require were also factors in selecting Pharmaquinone® as our K2 source. Both criteria, purity profile and reliable direct supply, were met. Pharmaquinone® is sourced directly from the original manufacturer.

Every ingredient sourced from its original maker

All four ingredients now come straight from the companies that produce them, rather than through a trader. It costs more, and the price reflects that.

The detail: what changed in this formulation and why ▾

This is a fully reformulated product. All four ingredients are now sourced directly from their original manufacturers. Here’s what changed and why:

What	New formulation	Why
Price	₹1,599 (₹2.67 per drop/day)	This formulation sources all four ingredients D3, K2, MCT oil, and Vitamin E directly from their original manufacturers. Direct sourcing from verified, branded ingredient suppliers carries a higher cost than our previous supply arrangement. The price reflects that. The bottle size reduction to 20ml was a parallel decision to manage per-unit cost while improving stability. We won’t suggest the economics are unchanged, because they aren’t.
Bottle size	20ml (~600 drops)	Smaller fill volume improves shelf life, reduces oxidation, and eliminates the leakage risk that occurred with larger fill volumes during storage and transport.
Vitamin D3	Vitashine® 600 IU per drop ✔ Verified direct-sourced	Vitashine® is UK-made, Vegan Society approved, lichen-derived. Sourced directly from the original manufacturer. Unchanged and confirmed.
Vitamin K2	Pharmaquinone® 20 mcg (Vitasynth, Poland)	Validated 100% all-trans MK-7 per US Pharmacopeia testing. Supply availability of our previous K2 source at the volume and consistency we require was a factor in the switch, alongside Pharmaquinone®’s purity profile. Sourced directly from the original manufacturer.
New addition	Mixed Tocopherols (Natural Vitamin E)	Natural antioxidant stabiliser that protects D3 and K2 from oxidative degradation during shelf life.
MCT Oil	Coconut-derived MCT Oil ✔ Verified direct-sourced	Sourced directly from the original manufacturer.

Four ingredients, nothing else

Vitamin D3, vitamin K2, coconut MCT oil to carry them, and natural vitamin E to keep them fresh. No emulsifiers, stabilisers or fillers.

The science: what each ingredient does ▾

Vitashine® Vitamin D3: 600 IU per drop (100% RDA), vegan D3 from lichen, manufactured in the UK, certified by the Vegan Society. Identical to the D3 your skin produces from sunlight. Not fish-derived, not wool-derived. Drives calcium absorption from the gut, supports immune cell production, and hundreds of downstream gene expression processes.
Pharmaquinone® Vitamin K2-MK7: 20 mcg per drop, validated 100% all-trans MK-7 per US Pharmacopeia testing (Vitasynth, Poland). Activates osteocalcin to direct calcium into bone matrix, and MGP, a protein involved in directing calcium to bone rather than soft tissue. Natural fermentation-derived MK-7 with a 72-hour half-life, supporting consistent tissue-level K2 activity.
MCT Oil: coconut-derived, medium-chain triglycerides provide the fat D3 and K2 require for absorption, without needing a full meal. No synthetic emulsifiers, stabilisers, or carriers.
Mixed Tocopherols (Natural Vitamin E): natural antioxidant stabiliser added in the reformulation. Protects D3 and K2 from oxidative degradation during storage and shelf life.

What it may support

Healthy bones
Normal immune function
Normal calcium absorption and use

The science: what each benefit is based on ▾

Bone mineral density: D3 drives calcium absorption; Pharmaquinone® K2 (100% all-trans MK-7) activates osteocalcin to direct calcium into bone matrix
Calcium regulation: K2 activates MGP, a protein involved in regulating where calcium is deposited in the body
Immune function: Vitamin D3 is required for the production and activation of immune cells.
Endocrine function: Vitamin D functions as a prohormone and is involved in normal endocrine signalling

How to use

Take 1 drop a day, or the dose your practitioner advises based on your vitamin D levels. Place it under the tongue or add it to any drink. Taking it with a meal that contains some fat helps absorption. Morning is ideal.

More on dosing, magnesium and storage ▾

Place 1 drop under the tongue or add to any beverage daily. Best taken with a meal containing fat, the MCT oil base reduces the requirement for additional fat, but absorption is enhanced alongside a fatty meal. Morning is ideal.

How long a bottle lasts depends on your dose:

Drops a day	Vitamin D3	Vitamin K2	One bottle lasts
1	600 IU	20 mcg	12 months (use within 12 months of opening)
2	1,200 IU	40 mcg	about 300 days
4	2,400 IU	80 mcg	about 150 days

Use within 12 months of opening, and before the expiry date on the bottle. Take more than 1 drop a day only on your practitioner’s advice. K2 rises with every drop, so the ratio of D3 to K2 stays the same at any dose.

Higher dosing: If your practitioner has recommended a loading dose (2–3 drops daily), confirm the duration.

Pair with Magnesium: Magnesium is required for the enzyme that converts Vitamin D to its active form (calcitriol). Taking D3 without adequate magnesium is one of the most common reasons D3 supplementation underperforms. iThrive Magnesium Bisglycinate is the natural pairing.

Storage: Store in a cool, dry place away from direct sunlight. Do not refrigerate. Use within 12 months of opening. The mixed tocopherols in this formula protect against oxidation during storage.

Practitioner’s Note

suyash bhandari ithrive supplements formulation

“The crux of this reformulation are the choice of K2 and the move to direct sourcing from original manufacturers. On K2, we chose Pharmaquinone® for two reasons. First, its validated purity profile: 100% all-trans MK-7 per US Pharmacopeia testing, with no cis isomer. The cis isomers of MK-7 have significantly reduced ability to activate the gamma-glutamylcarboxylase enzyme that carboxylates osteocalcin and MGP, the two K2-dependent proteins responsible for bone mineralisation and arterial calcium regulation. A supplement declaring 20 mcg of MK-7 on the label may contain a meaningful proportion of cis isomers that contribute to that number without contributing to the function. With Pharmaquinone®, the 20 mcg declared is 20 mcg of validated all-trans MK-7. Second, supply availability and sourcing consistency at the volumes we require, both criteria were met. On Vitamin E, the mixed tocopherols are a functional addition, not a filler. The smaller 20ml fill volume presents a higher surface-to-volume ratio, which increases relative oxidative exposure. The tocopherols protect the integrity of both D3 and K2 during shelf life. And on direct sourcing every ingredient in this bottle is now verified at origin. That is how it should always have been.”

Suyash Bhandari
In-House Scientist & Head of Formulations, iThrive Essentials

Essentials are not generic supplements sold alongside the program. They are the protocol.

Immunity