How Menaquinone-7 (MK-7), a simple nutrient, could revolutionize Polycystic Ovary Syndrome management
Polycystic Ovary Syndrome (PCOS) represents one of the most common endocrine disorders affecting women worldwide, with a staggering prevalence of 9-18% among women of reproductive age. In Iran, where a groundbreaking study was conducted, approximately 15.2% of women are affected by this condition 1 .
PCOS affects approximately 1 in 10 women of childbearing age, making it one of the most common endocrine disorders in this population.
Characterized by a complex interplay of symptoms including hormonal imbalances, irregular periods, ovarian cysts, insulin resistance, and fertility challenges, PCOS has long frustrated both patients and clinicians with its multifaceted nature.
Traditional PCOS management has typically involved a patchwork of approaches—lifestyle modifications, insulin-sensitizing medications, anti-androgen drugs, and fertility treatments. While these strategies provide relief for some symptoms, they often fail to address the root causes of the syndrome.
However, recent scientific investigations have uncovered a surprising ally in the fight against PCOS: a form of vitamin K known as menaquinone-7 (MK-7). This emerging research suggests that this often-overlooked nutrient might simultaneously target multiple aspects of the PCOS puzzle, from metabolic disturbances to hormonal imbalances and even mental health complications 1 3 .
Vitamin K exists in several forms, but MK-7, part of the vitamin K2 family, possesses unique properties that make it particularly beneficial. Unlike vitamin K1 (phylloquinone), which is primarily involved in blood clotting, MK-7 has demonstrated far-reaching effects throughout the body.
What sets MK-7 apart is its superior bioavailability and longer half-life compared to other vitamin K forms, allowing it to remain active in the bloodstream significantly longer and reach various tissues more effectively 4 .
MK-7 occurs naturally in certain fermented foods, with the Japanese fermented soybean dish natto being the richest known source. This explains why populations that regularly consume natto have higher MK-7 levels 4 .
While our gut bacteria also produce some forms of vitamin K, the absorption from this source is generally insufficient to meet our physiological needs, making dietary intake or supplementation important 4 .
The mechanisms through which MK-7 exerts its effects are multifaceted. It acts as an essential cofactor for enzymes that activate specific proteins involved in calcium metabolism, bone health, and cardiovascular function. More recently, researchers have discovered that MK-7 also influences insulin sensitivity, inflammatory pathways, and hormone regulation—all crucial factors in PCOS management 4 6 .
In 2020, a landmark study published in Food Science & Nutrition delivered compelling evidence for MK-7's potential in PCOS management. This randomized, double-blind, placebo-controlled trial—the gold standard in clinical research—was conducted at the Ghadir Mother & Child Hospital affiliated with Shiraz University of Medical Sciences in Iran 1 .
The study enrolled 84 women diagnosed with PCOS according to the Rotterdam criteria, the international standard for PCOS diagnosis.
Participants were randomly assigned to one of two groups: the treatment group received 90 micrograms of MK-7 daily for eight weeks, while the control group received an identical-looking placebo capsule containing inert material 1 .
Neither the participants nor the researchers knew who received which treatment until after the study was completed—a crucial design element that prevents biased interpretations.
To ensure that any changes observed could be confidently attributed to the MK-7 supplementation rather than other lifestyle factors, the researchers provided all participants with the same dietary recommendations for PCOS and asked them to maintain their usual physical activity levels.
The research team collected comprehensive data both before and after the intervention period, including:
Analyzed for insulin, glucose, lipids, and hormonal markers
Including weight, waist circumference, and body composition via bioelectrical impedance analysis
Of PCOS symptoms 1
This meticulous methodology allowed the researchers to isolate and identify the specific effects of MK-7 supplementation with remarkable precision.
The findings from the eight-week intervention revealed surprisingly broad-ranging benefits from this simple nutritional intervention. The MK-7 group demonstrated significant improvements across metabolic, endocrine, and body composition parameters compared to the placebo group 1 .
Increase in SHBG levels
Reduction in body fat mass
Perhaps the most striking improvements appeared in the realm of metabolic health. The MK-7 group experienced a significant reduction in insulin resistance—a fundamental driver of PCOS pathology. This was evidenced by notable decreases in fasting insulin levels and homeostasis model assessment of insulin resistance (HOMA-IR), along with increased quantitative insulin sensitivity check index (QUICKI) values. Additionally, triglyceride levels—a key blood lipid—showed marked improvement in the MK-7 group 1 .
The hormonal landscape of PCOS also shifted favorably with MK-7 supplementation. Participants demonstrated significant reductions in dihydrotestosterone (DHT)—a potent androgen responsible for many PCOS symptoms like hirsutism and acne. Equally important was the increase in sex hormone-binding globulin (SHBG), a protein that binds to testosterone in the bloodstream, effectively reducing the amount of biologically available androgen that can cause symptoms 1 .
| Parameter | Change with MK-7 | Statistical Significance | Clinical Importance |
|---|---|---|---|
| Fasting Insulin | Significant decrease | p = .002 | Reduces hyperinsulinemia driving PCOS |
| Insulin Resistance (HOMA-IR) | Significant decrease | p = .002 | Improves fundamental metabolic defect in PCOS |
| Triglycerides | Significant decrease | p = .003 | Lowers cardiovascular risk factor |
| Dihydrotestosterone (DHT) | Significant decrease | p = .03 | Reduces potent androgen activity |
| Sex Hormone-Binding Globulin (SHBG) | Significant increase | p < .001 | Decreases biologically available androgens |
Beyond the internal biochemical improvements, the MK-7 group experienced visible changes in their body composition. While body weight and BMI showed minimal changes, the distribution and proportion of body tissues shifted importantly. The MK-7 group lost significant amounts of body fat mass while simultaneously gaining skeletal muscle 1 .
This body recomposition is particularly relevant for PCOS management, as excess fat mass—especially abdominal fat—contributes to insulin resistance and inflammation, while skeletal muscle plays crucial roles in glucose metabolism and insulin sensitivity. The MK-7 group also demonstrated a significant reduction in waist circumference, indicating a favorable shift in fat distribution away from the metabolically dangerous abdominal region 1 .
| Body Composition Parameter | Change with MK-7 | Statistical Significance | Metabolic Implications |
|---|---|---|---|
| Body Fat Mass | Significant decrease | p < .001 | Reduces tissue contributing to insulin resistance |
| Skeletal Muscle Mass | Significant increase | p < .001 | Increases metabolically active tissue |
| Waist Circumference | Significant decrease | p = .03 | Indicates reduction in abdominal adiposity |
| Body Weight | No significant change | Not significant | Demonstrates specific body recomposition |
Following the compelling metabolic and hormonal findings, the same research team investigated another crucial aspect of PCOS—the frequently overlooked mental health dimension. Women with PCOS experience depression at significantly higher rates than the general population, attributed to a combination of hormonal influences, inflammatory processes, and the psychological impact of managing a chronic condition 3 5 .
"The finding that MK-7 supplementation significantly improved depression status compared to placebo represents a potential breakthrough in addressing the psychological burden of PCOS."
In this component of the study, researchers used the Beck Depression Inventory-II (BDI-II)—a validated psychological assessment tool—to measure depression symptoms before and after the 8-week intervention period. The results revealed that MK-7 supplementation significantly improved depression status compared to the placebo 5 .
The mechanism behind this psychological benefit may involve MK-7's ability to cross the blood-brain barrier and influence brain chemistry.
Vitamin K appears to regulate pathways that control inflammation in the brain and influence the production of compounds called ceramides.
This exciting finding suggests that MK-7 might offer a dual approach to PCOS management, addressing both physical and mental health aspects simultaneously.
The compelling results from the PCOS studies didn't emerge from vacuum—they relied on specific reagents, assessment tools, and methodological approaches that form the essential toolkit for MK-7 research.
| Research Tool | Specification/Description | Function in Research |
|---|---|---|
| MK-7 Supplement | 90 µg/day derived from fermented soybean (natto) | Intervention being tested |
| Placebo | Identical capsules containing avesil | Control for comparison |
| Body Composition Analyzer | Bioelectrical impedance analysis (BIA) using InBody S10 | Precisely measures fat mass, muscle mass, and other body composition parameters |
| Vitamin K Status Assessment | ELISA kits for vitamin K measurement | Quantifies vitamin K levels in blood samples |
| Hormonal Assays | Various biochemical analysis methods | Measures DHT, SHBG, and other endocrine markers |
| Depression Assessment | Beck Depression Inventory-II (BDI-II) questionnaire | Validated tool for quantifying depression symptoms |
| Dietary Monitoring | 3-day dietary records analyzed with Nutritionist-4 software | Controls for potential dietary confounding factors |
The implications of these research findings are substantial for the millions of women worldwide navigating the challenges of PCOS. The demonstration that a simple, well-tolerated nutritional supplement can simultaneously address multiple facets of this complex syndrome—insulin resistance, dyslipidemia, androgen excess, unfavorable body composition, and even depression—represents a potential paradigm shift in PCOS management 1 3 5 .
It's important to recognize that MK-7 supplementation appears most promising as an adjunct therapy rather than a replacement for foundational PCOS management strategies.
While these findings are compelling, researchers acknowledge that further investigation will help refine our understanding of MK-7's role in PCOS management. Larger studies across more diverse populations, longer-term follow-up, and research combining MK-7 with other evidence-based interventions will help establish optimal protocols for incorporating this promising nutrient into comprehensive PCOS care 1 .
As our understanding of PCOS continues to evolve beyond a narrow focus on reproductive symptoms to encompass the full spectrum of metabolic, endocrine, and psychological dimensions, multifaceted approaches like MK-7 supplementation that address these interconnected systems simultaneously offer new hope for more effective and holistic management strategies. The emerging science of MK-7 reminds us that sometimes solutions to complex health challenges can be found in unexpected places—including nutrients we're just beginning to fully understand.