How Much Vitamin D3 and K2 Per Day? Where 4,000 IU Fits

Most adults need 600 IU of vitamin D a day (800 IU from age 71), and 4,000 IU is the adult upper limit from food, drinks and supplements combined. Those are the NIH Office of Dietary Supplements figures. K2 has no official amount of its own: the Adequate Intake of 90 mcg for women and 120 mcg for men covers every form of vitamin K, and a three-year MK-7 trial used 180 mcg a day. So where does 4,000 IU fit? It is the higher-dose end of the range, the right call when your needs or your clinician point there, and it is exactly what one capsule of our Vegan D3 + K2 delivers.

How much vitamin D3 and K2 should you take daily?

For vitamin D, the official numbers are refreshingly simple. The Recommended Dietary Allowance (RDA) is 600 IU (15 mcg) a day for ages 1 to 70 and 800 IU (20 mcg) from age 71, and the Tolerable Upper Intake Level (UL) is 4,000 IU (100 mcg) a day for everyone 9 and older, according to NIH ODS. The RDA is set to cover nearly all (97 to 98%) healthy people, and it already assumes you get minimal sun.

For vitamin K, the Food and Nutrition Board set an Adequate Intake instead of an RDA: 120 mcg a day for men and 90 mcg for women. That figure counts all vitamin K, much of it K1 from leafy greens and vegetable oils. There is no separate official amount for K2 or MK-7.

Your personal number depends on your diet, your sun exposure, your blood level if you have been tested, and your medicines. Add up every source before you choose a dose: a multivitamin with 1,000 IU plus a 4,000 IU capsule is 5,000 IU, which is over the line.

Vitamin D3: daily needs vs the upper limit

The gap between what you need and the most you should take is wide, which is why labels in the supplement aisle can look like they are shouting different numbers at you. Here are both figures by age from the NIH ODS vitamin D fact sheet. To convert between units, 1 mcg of vitamin D equals 40 IU.

Vitamin D: daily recommendation vs upper limit by age (NIH ODS)

Age	Daily recommendation	Upper limit (all sources)
0–6 months	400 IU (10 mcg), Adequate Intake	1,000 IU (25 mcg)
7–12 months	400 IU (10 mcg), Adequate Intake	1,500 IU (38 mcg)
1–3 years	600 IU (15 mcg)	2,500 IU (63 mcg)
4–8 years	600 IU (15 mcg)	3,000 IU (75 mcg)
9–18 years	600 IU (15 mcg)	4,000 IU (100 mcg)
19–70 years	600 IU (15 mcg)	4,000 IU (100 mcg)
71 years and older	800 IU (20 mcg)	4,000 IU (100 mcg)
Pregnancy and breastfeeding	600 IU (15 mcg)	4,000 IU (100 mcg)

Labels add a third number, the Daily Value, which the FDA sets at 800 IU (20 mcg) for adults and children 4 and older. That is why any 4,000 IU product shows 500% DV: dramatic-looking, but simply the adult UL written as a percentage.

The way to know whether you are getting enough is a blood test for 25-hydroxyvitamin D, written 25(OH)D. The Food and Nutrition Board considers 50 nmol/L (20 ng/mL) or more sufficient for most people, and deficiency risk rises below 30 nmol/L (12 ng/mL).

Is 4,000 IU of vitamin D3 too much?

For adults, 4,000 IU a day is not too much; it is the ceiling. The UL is the highest daily intake unlikely to cause adverse health effects, counted across every source.

Why not aim for the ceiling anyway? Because in generally healthy older adults not selected for deficiency, more has not meant better. One of the few long-term tests of daily doses at or above 4,000 IU is a three-year double-blind trial of 311 healthy adults aged 55 to 70 without osteoporosis, who took 400, 4,000 or 10,000 IU a day. The higher doses did not build bone. At three years, radial bone density had fallen 2.4% in the 4,000 IU group and 3.5% in the 10,000 IU group, versus 1.2% with 400 IU. Tibial density was significantly lower only at 10,000 IU, and bone strength did not differ between groups.

In line with this, the 2024 Endocrine Society guideline suggests against routinely taking more than the Dietary Reference Intake to lower disease risk in healthy adults under 75. It does not cover people with an established reason for vitamin D treatment. That is where a 4,000 IU capsule earns its place: when your needs or your clinician call for more than the RDA, such as the groups below.

Where common daily vitamin D doses sit for adults (sources: NIH ODS, LeBoff 2022, Burt 2019)

Daily dose	What it is	What the evidence says
600 IU (15 mcg)	RDA, ages 1–70	Covers nearly all healthy people in this age range.
800 IU (20 mcg)	RDA from age 71; the label Daily Value	The recommended intake for older adults.
2,000 IU (50 mcg)	The dose used in VITAL	No fewer fractures than placebo over a median 5.3 years in 25,871 adults not selected for deficiency.
4,000 IU (100 mcg)	Adult upper limit from all sources	No bone-density benefit over 400 IU across three years in healthy adults aged 55–70 (radial density slightly lower).
10,000 IU (250 mcg)	Above the upper limit	Larger bone density decline than 400 IU at both the radius and tibia in the same trial. Clinician-supervised use only.

What about 5,000 or 10,000 IU a day?

Both are above the adult upper limit, so they belong in a plan your clinician supervises with blood tests, not in a routine you set for yourself. Take 5,000 IU daily and you are over the UL every day. The Food and Nutrition Board says toxicity symptoms are unlikely below 10,000 IU a day, but it notes that even intakes under the UL might have adverse effects over time and recommends keeping blood 25(OH)D below roughly 125 to 150 nmol/L (50 to 60 ng/mL). Nearly all vitamin D toxicity comes from supplements.

Too much vitamin D raises blood calcium (hypercalcemia). That can bring nausea, vomiting, muscle weakness, pain, loss of appetite, dehydration, frequent urination, excessive thirst and kidney stones; in extreme cases, kidney failure, soft-tissue calcification and irregular heart rhythm.

Adding K2 does not change the math: the upper limit counts vitamin D from all sources, with or without K2.

How much K2 should you take with D3?

There is no official K2 dose and no official D3-to-K2 ratio, so choose an amount in line with studied doses that fits your medicines. Neither the NIH vitamin K fact sheet nor the Endocrine Society guideline sets a ratio, whatever confident ratios circulate online. So "how much K2 with 5,000 IU of D3?" has no formula answer; the bigger question is the D3, since 5,000 IU is above the adult UL.

The Adequate Intake of 90 mcg (women) and 120 mcg (men) covers vitamin K from all foods and supplements. For MK-7 specifically, the best long-term reference point is a three-year trial of 244 healthy postmenopausal women who took 180 mcg of MK-7 a day or a placebo. MK-7 improved their vitamin K status, and the age-related decline in bone mineral content and density was smaller at the lumbar spine and femoral neck, though not at the total hip.

There is no upper limit for vitamin K (more on 200 mcg below), and MK-7 is well absorbed with a longer half-life than synthetic K1. For the background on the molecule itself, see what vitamin K2 (MK-7) is and what it does.

The big exception is warfarin and other vitamin K antagonists. In a dose-response study of 18 healthy volunteers taking the anticoagulant acenocoumarol, 45 mcg of MK-7 a day lowered average INR (International Normalized Ratio, the clotting test these drugs are dosed by) by about 40%. Even 10 and 20 mcg caused a clinically relevant INR drop in at least 40% and 60% of participants, and the authors advise avoiding MK-7 during this therapy. People on these drugs need a steady vitamin K intake, so do not start, stop or change K2 without your prescriber.

Who may need a different amount?

The RDA is built for healthy people. NIH ODS lists these groups as more likely to run low on vitamin D:

• Older adults. Skin makes less vitamin D with age, and older adults tend to spend more time indoors.
• People with limited sun exposure, such as homebound people or those whose clothing or job keeps their skin covered.
• People with darker skin, because more melanin reduces how much vitamin D skin makes from sunlight.
• People with conditions that limit fat absorption, such as Crohn's disease, celiac disease, cystic fibrosis, ulcerative colitis and some liver diseases. Vitamin D is fat-soluble, so its absorption depends on the gut absorbing fat.
• People with obesity or a history of gastric bypass surgery. Body fat holds onto more vitamin D, and people with obesity might need greater intakes to reach the same blood level.

The Endocrine Society separately suggests vitamin D above the Dietary Reference Intake for ages 1 to 18, adults 75 and older, pregnancy and high-risk prediabetes, without fixing an optimal dose. Children have lower upper limits (see the table above), so adult-strength products are for adults. The panel also suggests against routine 25(OH)D testing, so a blood test makes sense when your clinician has a specific reason for it.

Medicines matter too. NIH ODS notes that orlistat can reduce vitamin D absorption, steroids can impair vitamin D metabolism, and thiazide diuretics combined with vitamin D supplements might lead to high blood calcium, especially in older adults. A pharmacist can check your full list.

Quick answers

Is it better to take D3 and K2 in the morning or at night?

Neither has been shown to beat the other. What matters more is taking it with a meal, since vitamin D is fat-soluble, at a time you will actually remember. Our guide on when to take D3 and K2 covers timing in detail.

Can you take vitamin D with a statin such as rosuvastatin?

Ask the prescriber who manages your statin. NIH ODS notes that high vitamin D intakes, especially from supplements, might reduce the potency of atorvastatin, lovastatin and simvastatin, because they appear to compete for the same metabolizing enzyme. Rosuvastatin is not on that list, which is not the same as a green light, so let your prescriber or pharmacist review your regimen.

Is 200 mcg of vitamin K2 too much?

For healthy adults, there is no upper limit to measure it against: the Food and Nutrition Board set no UL for vitamin K, noting that no adverse effects from food or supplements have been reported. 200 mcg is close to the 180 mcg MK-7 dose used for three years in the postmenopausal women's trial. Anyone on warfarin or a similar anticoagulant is the exception and should ask their prescriber first.

Do you need K2 if you take D3?

Not automatically. No official guideline requires K2 alongside D3, and plenty of people take vitamin D on its own. People pair them because the jobs complement each other: vitamin D promotes calcium absorption, and vitamin K activates proteins involved in bone metabolism and blood clotting. Read more about why D3 and K2 are taken together.

Where Vegan D3 + K2 fits

If 4,000 IU fits your needs, or your clinician has recommended more than the RDA, Infinite Labs Vegan D3 + K2 is a strong pick that keeps it to one capsule a day. Each veggie capsule delivers 4,000 IU (100 mcg) of vitamin D3 from lichen, a plant-based D3 source, and 100 mcg of vitamin K2 as MK-7, with 60 servings per bottle. For non-pregnant adults over 50 who need vitamin D, the Endocrine Society prefers daily dosing over occasional large doses, and a one-a-day capsule fits that pattern.

The formula pairs the D3 with coconut MCT oil powder as its oil carrier, a deliberate choice for a fat-soluble vitamin, and the label pairs each capsule with food for the same reason. NIH ODS notes that fat in the gut enhances vitamin D absorption. In a randomized study of 50 healthy older adults who each took a single 50,000 IU dose of D3 with breakfast, blood D3 peaked significantly higher when the meal contained fat (30% of calories) than when it was fat-free.

The directions are straightforward: adults take one capsule daily with food, or as recommended by a qualified healthcare professional. Do not combine it with other high-dose vitamin D supplements, and check with your healthcare professional if you take medication, especially blood thinners, given the K2. The capsule is third-party tested and made in GMP-certified facilities, and certificates of analysis are available on request. Still comparing options? Our guide on how to choose a D3 + K2 supplement walks through doses, K2 forms and labels.

The practical takeaway

• Add it all up. 600 IU of vitamin D a day covers most adults (800 IU from 71). Count every source and stay at or under 4,000 IU; higher doses need a clinician and blood tests.
• Match K2 to your medicines. No official ratio, no upper limit, but warfarin users talk to their prescriber first.
• Test with a reason. Get a 25(OH)D test when your clinician recommends it. If 4,000 IU is your number, one capsule with a meal keeps it simple.

Sources

• NIH Office of Dietary Supplements: Vitamin D, Fact Sheet for Health Professionals (updated June 27, 2025).
• NIH Office of Dietary Supplements: Vitamin K, Fact Sheet for Health Professionals (updated March 29, 2021).
• Demay MB et al. Vitamin D for the Prevention of Disease: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab, 2024.
• Burt LA et al. Effect of High-Dose Vitamin D Supplementation on Volumetric Bone Density and Bone Strength. JAMA, 2019.
• LeBoff MS et al. Supplemental Vitamin D and Incident Fractures in Midlife and Older Adults. N Engl J Med, 2022.
• Knapen MH et al. Three-year low-dose menaquinone-7 supplementation in healthy postmenopausal women. Osteoporos Int, 2013.
• Theuwissen E et al. Effect of low-dose supplements of menaquinone-7 on the stability of oral anticoagulant treatment. J Thromb Haemost, 2013.
• Dawson-Hughes B et al. Dietary fat increases vitamin D-3 absorption. J Acad Nutr Diet, 2015.

Educational information, not medical advice. Infinite Labs Vegan D3 + K2 is not intended to diagnose, treat, cure, or prevent any disease.