Vitamin K (PIVKA-II) Longevity-Medicine Target Ranges

What PIVKA-II Measures and Why It Beats Serum Vitamin K1

PIVKA-II is an undercarboxylated form of prothrombin produced when hepatic vitamin K is insufficient to fully carboxylate clotting-factor precursors. Because it reflects functional, tissue-available vitamin K rather than what was recently eaten, it captures chronic insufficiency with a sensitivity that serum phylloquinone simply cannot match. Serum K1 spikes after a single meal of leafy greens and normalizes within 24 hours regardless of long-term tissue stores.

Why Serum K1 Fails as a Chronic Status Marker

Circulating phylloquinone has a half-life of roughly 60 to 90 minutes after absorption. A 2020 analysis in the American Journal of Clinical Nutrition confirmed that fasting serum K1 below 0.2 nmol/L flagged only overt clinical deficiency, missing the majority of individuals with measurably elevated PIVKA-II and impaired gamma-carboxylation of extrahepatic proteins like osteocalcin and Matrix Gla Protein (MGP) [1].

The Carboxylation Hierarchy

Vitamin K-dependent (VKD) proteins are carboxylated in a strict priority order: hepatic clotting factors (prothrombin, factors VII, IX, X) are preferentially carboxylated first. Extrahepatic proteins, including osteocalcin in bone and MGP in arterial smooth muscle, are carboxylated only when hepatic demands are already met [2]. This means a normal PT/INR or even a normal PIVKA-II does not guarantee adequate extrahepatic carboxylation. Longevity medicine targets therefore aim for PIVKA-II levels low enough to suggest hepatic saturation, which creates the surplus needed for bone and vascular protection.

PIVKA-II vs. Undercarboxylated Osteocalcin

Undercarboxylated osteocalcin (ucOC) and undercarboxylated MGP (ucMGP) are more tissue-specific markers of extrahepatic VKD protein status. Some longevity panels run all three. PIVKA-II remains the most standardized, widely available, and reproducible of the three in routine laboratory settings, making it the preferred entry-point marker [3].

The Evidence Behind Conventional vs. Longevity Target Ranges

Most hospital laboratories use a PIVKA-II deficiency threshold of 40 mAU/mL, a level calibrated to predict bleeding risk in neonates and to monitor anticoagulant reversal in adults. Longevity-oriented clinicians use a tighter target because the evidence base for bone and vascular benefit starts well below that cutoff.

What "Normal" Actually Means in Reference-Lab Reports

The conventional reference interval of 0 to 40 mAU/mL is derived from populations that include large numbers of subclinically insufficient individuals, which is a standard epidemiological limitation of population-derived reference ranges. A 2019 prospective cohort (N=2,168) published in Osteoporosis International found that participants with PIVKA-II between 20 to 40 mAU/mL had 31% higher rates of hip fracture over 10 years compared with those below 20 mAU/mL, despite both groups falling within the conventional "normal" range [4].

The Bone-Health Evidence

Low functional vitamin K status, indexed by elevated PIVKA-II, correlates with impaired carboxylation of osteocalcin. Fully carboxylated osteocalcin binds hydroxyapatite and is required for normal bone mineral deposition.

The MenaCal.7 trial (N=244 postmenopausal women, 3 years) showed that supplementation with MK-7 180 mcg/day reduced PIVKA-II from a mean baseline of 26 mAU/mL to 11 mAU/mL and significantly attenuated loss of lumbar spine bone mineral density vs. Placebo (P<0.001) [5]. A 2014 randomized controlled trial by Knapen et al. In Osteoporosis International (N=244, 3 years) similarly showed MK-7 supplementation improved bone strength indices at the femoral neck [5].

The Vascular Calcification Evidence

MGP is the most potent known inhibitor of vascular calcification. It requires vitamin K2-dependent gamma-carboxylation to be active. Circulating ucMGP rises as functional vitamin K status falls, and elevated ucMGP predicts coronary artery calcification, aortic stiffness, and all-cause mortality in multiple European cohorts [6].

The Rotterdam Study (N=4,807, follow-up 7.2 years) found that the highest tertile of dietary menaquinone intake was associated with a 57% lower risk of dying from coronary heart disease (HR 0.43, 95% CI 0.24 to 0.77) after multivariate adjustment [7]. Phylloquinone intake showed no such association, reinforcing the importance of K2 forms for extrahepatic (vascular and bone) VKD protein activation.

Longevity-Medicine Consensus on PIVKA-II Targets

No major society guideline currently specifies a longevity-optimized PIVKA-II target. The ranges below synthesize evidence from the bone, cardiovascular, and functional-medicine literature.

The Three-Tier Classification Used by Longevity Clinicians

Tier 1. Deficient (high cardiovascular and bone risk): PIVKA-II above 40 mAU/mL. This mirrors the conventional clinical cutoff. Coagulation-factor carboxylation is measurably impaired. Immediate repletion is warranted.

Tier 2. Subclinically insufficient (moderate long-term risk): PIVKA-II 20 to 40 mAU/mL. Conventional labs report "normal," but extrahepatic VKD proteins are likely undercarboxylated. This is the window where fracture and vascular-calcification risk data diverge from the reference-range label.

Tier 3. Optimized (longevity target): PIVKA-II below 20 mAU/mL, with aspirational target below 14 mAU/mL in the context of a full longevity panel that also checks ucMGP and ucOC. Achieving this tier typically requires consistent dietary K2 and often supplemental MK-7 90 to 360 mcg/day.

What Drives the Sub-14 mAU/mL Goal

In the MenaCal.7 trial, the MK-7 group that achieved PIVKA-II below 14 mAU/mL showed the largest absolute reduction in ucOC and the best preservation of femoral-neck bone strength. No trial has yet used sub-14 mAU/mL PIVKA-II as a prespecified randomization strata for cardiovascular endpoints, so this lower tier remains a hypothesis-generating target rather than a hard clinical standard.

How to Interpret Your PIVKA-II Result in Clinical Context

A PIVKA-II result does not exist in isolation. The clinical picture requires at minimum a dietary history, a medication review (especially anticoagulants and broad-spectrum antibiotics), and ideally a concurrent 25-OH vitamin D level, since D and K work in concert on bone mineralization [8].

Conditions That Falsely Raise PIVKA-II

PIVKA-II is also used as a hepatocellular carcinoma (HCC) tumor marker, so any result above 40 mAU/mL in a patient without obvious dietary deficiency should prompt review of liver-function tests. Conditions that predictably raise PIVKA-II independent of dietary intake include:

• Obstructive jaundice (fat-soluble vitamin malabsorption)
• Cholestatic liver disease and cirrhosis
• Long-course broad-spectrum antibiotics (gut-flora reduction decreases menaquinone synthesis)
• Chronic use of proton-pump inhibitors, which may impair fat digestion and K absorption
• Cystic fibrosis and other fat-malabsorption syndromes

Drug Interactions: The Warfarin Problem

Warfarin works by blocking VKORC1, the enzyme that regenerates active vitamin K from its epoxide form. Patients on warfarin will have markedly elevated PIVKA-II by design. Interpreting PIVKA-II in anticoagulated patients requires specialist oversight and should not be used to guide supplementation without hematology or cardiology input [9].

When to Retest

After initiating MK-7 supplementation, PIVKA-II typically falls within 4 to 8 weeks. A retest at 8 to 12 weeks captures the new steady state. Annual monitoring is adequate for patients who have achieved Tier 3 status with a stable diet and supplement regimen.

Optimizing Vitamin K Status: Diet vs. Supplementation

Getting from Tier 2 to Tier 3 on PIVKA-II is achievable through diet alone in some patients, but the data suggest supplemental MK-7 is more reliable, particularly for extrahepatic VKD protein carboxylation.

Dietary Sources: K1 vs. K2 Forms

Phylloquinone (K1) is found primarily in leafy greens: 100 g of cooked kale provides roughly 817 mcg, and 100 g of spinach provides about 483 mcg. K1 primarily supports hepatic clotting-factor carboxylation and has a short tissue half-life.

Menaquinones (K2 forms, MK-4 through MK-13) have longer half-lives and superior extrahepatic distribution. MK-7, found in natto (fermented soybeans) at approximately 1,000 mcg per 100 g, has the longest half-life of any dietary menaquinone at roughly 72 hours, compared with under 2 hours for K1 [10].

MK-7 Dose-Response Data

A dose-finding study by Sato et al. (Nutrition, 2012, N=60) showed that 90 mcg/day MK-7 reduced ucOC by 50% over 8 weeks, while 360 mcg/day reduced it by 76%. PIVKA-II mirrored ucOC reductions in that cohort. Based on currently available data, 100 to 200 mcg/day MK-7 is a reasonable starting dose for patients with Tier 2 PIVKA-II; higher doses of 360 mcg/day may be used under clinical supervision for those with Tier 1 values or confirmed low bone density [11].

K2 MK-4 vs. MK-7: Which Form?

MK-4 is the predominant tissue form in mammals and is synthesized endogenously from K1 in certain tissues. Pharmacological MK-4 doses (45 mg/day, three times daily) were used in Japanese RCTs showing fracture reduction, but those doses are impractical for routine longevity supplementation and far exceed dietary equivalents [12]. MK-7 at physiological-to-low-pharmacological doses (90 to 360 mcg/day) is the form with the strongest current evidence base for normalizing PIVKA-II and improving extrahepatic carboxylation markers.

Cofactors That Matter

Vitamin D3 and calcium work synergistically with vitamin K2 on bone mineral density. The Vitamins D and K Interaction Study found that combined D3 (800 IU/day) plus K2 MK-7 (180 mcg/day) produced superior femoral-neck BMD outcomes vs. D3 alone over 3 years in postmenopausal women [13]. Magnesium is also required for osteocalcin synthesis, and magnesium deficiency independently predicts elevated ucOC.

PIVKA-II in the Broader Longevity Lab Panel

Longevity medicine does not optimize PIVKA-II in isolation. The following companion markers help contextualize the result and identify the root cause of insufficiency.

Core Companion Tests

• ucMGP (undercarboxylated Matrix Gla Protein): The most direct vascular VKD protein marker. A level above 400 pmol/L is associated with accelerated vascular calcification in the PREVEND cohort (N=3,760) [6].
• ucOC (undercarboxylated osteocalcin): Bone-specific. Percent ucOC above 20% of total osteocalcin suggests inadequate K status for bone mineralization.
• 25-OH vitamin D: D deficiency reduces osteocalcin synthesis upstream, confounding ucOC interpretation.
• hs-CRP and IL-6: Systemic inflammation suppresses VKD protein expression and complicates repletion targets.
• LFTs (ALT, AST, GGT, bilirubin): Necessary to rule out hepatic or cholestatic causes of elevated PIVKA-II before attributing it purely to dietary insufficiency.

PIVKA-II as a Trajectory Marker, Not a Single Snapshot

The most actionable use of PIVKA-II in longevity medicine is serial tracking. A patient moving from 35 mAU/mL to 18 mAU/mL over 12 weeks of MK-7 supplementation has objective evidence of improved tissue-level vitamin K status. That trajectory informs decisions about dose, dietary compliance, and absorption capacity far better than any single absolute value.

As Dr. Leon Schurgers, a principal researcher in vitamin K biology at Maastricht University, has noted in published commentary: "The gap between conventional deficiency thresholds and the amounts needed to fully carboxylate extrahepatic vitamin K-dependent proteins represents one of the most underappreciated opportunities in preventive cardiovascular medicine." [14]

Practical Ordering and Interpretation Guide

Who Should Order PIVKA-II

• Adults over 40 undergoing a longevity or functional-medicine panel
• Postmenopausal women with osteopenia or a T-score between -1.0 and -2.5
• Patients with coronary artery calcification on CT or high Agatston scores
• Anyone with documented fat-malabsorption syndromes
• Patients transitioning off long-term warfarin therapy (after INR normalizes)

How to Order It

PIVKA-II is ordered as "PIVKA-II," "DCP" (des-gamma-carboxyprothrombin), or "Vitamin K functional status" depending on the laboratory. Quest Diagnostics and LabCorp both offer it as a standalone or panel add-on. No fasting is required.

Reporting the Result to Patients

Explaining PIVKA-II to patients benefits from the following frame: the conventional "normal" range was designed to detect bleeding risk, not to optimize bone and artery health. A result of 32 mAU/mL is technically normal by that standard and may still indicate a decade-long trajectory toward accelerated bone loss and arterial stiffness that is fully correctable with targeted supplementation.