Thorne Vitamin D + K2 Liquid is the D3-plus-K2 and liquid pick of our vitamin D roundup (81/100). Its sticker — about $34 for a 1 fl oz dropper bottle — reads as a premium against a jar of generic softgels, and that first impression is why buyers overpay attention to the wrong number. The number that matters is cost per serving, and once you divide $34 by roughly 600 two-drop servings, the picture flips. We pulled Thorne’s published pricing, checked July 2026, and turned it into the three figures that count: per serving, per month, per year.
The cost, in one table
Thorne sells one product here — a 1 fl oz bottle of D3 and K2 suspended in MCT oil — sold outright through major retailers and Thorne’s own channels, with no subscription-first auto-ship to cancel. A single bottle holds about 600 two-drop servings, which at one serving a day is close to a 20-month supply, so the monthly and yearly figures below matter far more than the sticker on the bottle. Figures checked July 2026.
| Bottle price (1 fl oz, ~600 servings) | ~$34 | one-time, no subscription needed |
|---|---|---|
| Cost per serving (1,000 IU D3 + 200 mcg K2) | ~$0.06 | cheapest D3-plus-K2 in our comparison |
| Cost per month (~30 servings) | ~$1.70 | daily use at 1,000 IU |
| Cost per year (~365 servings) | ~$21 | one bottle lasts ~20 months |
| If you run 2,000 IU (4 drops) | ~$0.12 | ~$44 a year; still cheap, and adds K2 |
What that buys next door
The honest comparison has to account for two things at once: dose and the K2. At its native 1,000 IU serving Thorne is the cheapest option in our comparison at about $0.06, and it is the only one that includes K2 at that price. The plain D3 softgels our rubric scores higher cost more per serving and carry no K2: Nature Made Vitamin D3 2,000 IU (87/100), our best overall and best value, runs about $0.13 a serving (roughly $47 a year, USP Verified, D3-only), and NOW Vitamin D-3 2,000 IU (84/100), the cheapest plain D3, lands near $0.07 (about $26 a year, D3-only). Note those deliver 2,000 IU to Thorne’s 1,000; run Thorne at a matching 2,000 IU (four drops) and it is about $0.12 a serving, on par with Nature Made — but with 200 mcg of K2 added. So the premium framing is backwards: Thorne is not the expensive combo, it is a genuinely cheap one whose sticker just hides a 20-month supply. What the money does not buy is the longer-acting K2 form — the K2 here is MK-4, not the more efficient MK-7 — and the drops trade a fixed softgel’s convenience for the ability to titrate. Whether you need the K2 at all is the real question; the alternatives page lays out the plain-D3 and MK-7 routes.
Frequently asked questions
How much does Thorne Vitamin D + K2 Liquid cost per serving?
About $0.06 a serving, based on a ~$34 bottle of roughly 600 two-drop servings, each delivering 1,000 IU of D3 and 200 mcg of K2, checked July 2026. That is the cheapest way to get a combined D3-plus-K2 product in our comparison — the $34 sticker just hides that one bottle is close to a 20-month supply.
Is Thorne Vitamin D + K2 Liquid actually expensive?
No — that is the common misread. The bottle looks premium next to a jar of generic softgels, but divided across ~600 servings it works out to about $1.70 a month and roughly $21 a year at 1,000 IU. Even run at a 2,000 IU dose (four drops) it is about $0.12 a serving, on par with our best-value plain D3 — and it adds K2.
Does Thorne Vitamin D + K2 Liquid have a subscription?
No. It is sold outright through major retailers and Thorne’s own channels rather than a subscription-first auto-ship, so you can buy a bottle without enrolling in recurring shipments — which spares you the cancellation friction common to DTC supplement brands.
How does the cost compare to plain vitamin D?
At its 1,000 IU serving Thorne is cheaper per serving than the plain D3 softgels our roundup scores higher — Nature Made runs about $0.13 and NOW about $0.07, both D3-only at 2,000 IU. The trade is dose and K2: match Thorne to 2,000 IU and it is about $0.12, but it is the only one of the three that includes K2.
Sources
- Thorne — official product and pricing pages (1,000 IU D3 as cholecalciferol plus 200 mcg K2 as MK-4 per 2-drop serving, MCT-oil base, vegetarian, ~600 servings per 1 fl oz bottle, ~$34, NSF Contents Certified). Checked July 2026. thorne.com
- The Ingredient Report — Thorne Vitamin D + K2 Liquid review (81/100), the vitamin D roundup, and scored reviews of Nature Made Vitamin D3 (87/100) and NOW Vitamin D-3 (84/100). Checked July 2026.
Update history
- July 17, 2026 — Page first published. Facts checked this date. Next check: August 2026.
Content is for informational purposes only and is not medical or financial advice. Medical disclaimer.