Vitamin K2 (MK-7)

Efficacy of different routes of vitamin B12 supplementation for the treatment of patients with vitamin B12 deficiency: A systematic review and network meta-analysis.

Abdelwahab OA, Abdelaziz A, Diab S, Khazragy A, Elboraay T, Fayad T · Irish journal of medical science · 2024 · n=4275

This systematic review and network meta-analysis aimed to evaluate the three different administration routes of vitamin B12: oral, intramuscular (IM), and sublingual (SL) routes. We searched four electronic databases (PubMed, Scopus, Web of Science, and Cochrane CENTRAL Register of Controlled Trials). We included only comparative studies. We performed a frequentist network meta-analysis to measure network estimates for the relative outcomes. Moreover, we conducted a pairwise meta-analysis using a random effect model to obtain direct estimates for outcomes. All outcomes were continuous, and the relative treatment effects were pooled as mean difference (MD) with 95% confidence intervals. Thirteen studies were included in the meta-analysis, with a total of 4275 patients. Regarding increasing vitamin B12 levels, the IM route ranked first, followed by the SL route (MD = 94.09 and 43.31 pg/mL, respectively) compared to the oral route. However, these differences did not r

Bariatric Surgery in Obesity: Effects on Gut Microbiota and Micronutrient Status.

Ciobârcă D, Cătoi AF, Copăescu C, Miere D, Crișan G · Nutrients · 2020

Obesity is associated with reduced gut microbial diversity and a high rate of micronutrient deficiency. Bariatric surgery, the therapy of choice for severe obesity, produces sustained weight loss and improvements in obesity-related comorbidities. Also, it significantly alters the gut microbiota (GM) composition and function, which might have an important impact on the micronutrient status as GM is able to synthesize certain vitamins, such as riboflavin, folate, B12, or vitamin K2. However, recent data have reported that GM is not fully restored after bariatric surgery; therefore, manipulation of GM through probiotics represents a promising therapeutic approach in bariatric patients. In this review, we discuss the latest evidence concerning the relationship between obesity, GM and micronutrients, the impact of bariatric surgery on GM in relation with micronutrients equilibrium, and the importance of the probiotics' supplementation in obese patients submitted to surgical treatment.

The additive effect of vitamin K supplementation and bisphosphonate on fracture risk in post-menopausal osteoporosis: a randomised placebo controlled trial.

Moore AE, Dulnoan D, Voong K, Ayis S, Mangelis A, Gorska R · Archives of osteoporosis · 2023 · n=105

This study assessed whether vitamin K, given with oral bisphosphonate, calcium and/or vitamin D has an additive effect on fracture risk in post-menopausal women with osteoporosis. No difference in bone density or bone turnover was observed although vitamin K1 supplementation led to a modest effect on parameters of hip geometry. Some clinical studies have suggested that vitamin K prevents bone loss and may improve fracture risk. The aim was to assess whether vitamin K supplementation has an additive effect on bone mineral density (BMD), hip geometry and bone turnover markers (BTMs) in post-menopausal women with osteoporosis (PMO) and sub-optimum vitamin K status receiving bisphosphonate, calcium and/or vitamin D treatment. We conducted a trial in 105 women aged 68.7[12.3] years with PMO and serum vitamin K1 ≤ 0.4 µg/L. They were randomised to 3 treatment arms; vitamin K1 (1 mg/day) arm, vitamin K2 arm (MK-4; 45 mg/day) or placebo for 18 mo

Three-year low-dose menaquinone-7 supplementation helps decrease bone loss in healthy postmenopausal women.

Knapen MH, Drummen NE, Smit E, Vermeer C, Theuwissen E · Osteoporosis international : a journal established as result of cooperation between the European Foundation for Osteoporosis and the National Osteoporosis Foundation of the USA · 2013

We have investigated whether low-dose vitamin K2 supplements (menaquinone-7, MK-7) could beneficially affect bone health. Next to an improved vitamin K status, MK-7 supplementation significantly decreased the age-related decline in bone mineral density and bone strength. Low-dose MK-7 supplements may therefore help postmenopausal women prevent bone loss. Despite contradictory data on vitamin K supplementation and bone health, the European Food Safety Authorities (EFSA) accepted the health claim on vitamin K's role in maintenance of normal bone. In line with EFSA's opinion, we showed that 3-year high-dose vitamin K1 (phylloquinone) and K2 (short-chain menaquinone-4) supplementation improved bone health after menopause. Because of the longer half-life and greater potency of the long-chain MK-7, we have extended these investigations by measuring the effect of low-dose MK-7 supplementation on bone health. Healthy postmenopausal women (n = 244) received for 3 years placebo o

Vitamin and trace elements imbalance are very common in adult patients with newly diagnosed Celiac disease.

Nuermaimaiti K, Li T, Li N, Shi T, Liu W, Abulaiti P · Scientific reports · 2025

Patients with celiac disease are at risk of micronutrient deficiencies due to long-term inflammation of the small intestine. Therefore, our aim was to investigate the correlation between CeD and micronutrients. A cross-sectional study enrolled a total of 59 newly diagnosed celiac patients and 59 controls. Levels of 17 vitamins and 10 trace elements were measured. Symptoms, serum IgA anti-TG2 (tTG-IgA), BMI, albumin, hemoglobin, and Marsh classification were recorded. The levels of micronutrients were compared between cases and controls, and correlations between micronutrients and other factors were analyzed. Celiac patients had lower levels of BMI, albumin, hemoglobin, vitamins A, E, K2 (MK-7, MK-4), B6, and B7, as well as zinc, and higher levels of vitamin B3 and chromium than controls (p < 0.05). The deficiency rates of vitamins A, E, and K2 (MK-7) and the excess rate of vitamin B3 were significantly higher than in controls (p < 0.05). Vitamin C, iro

New Insights into Folate-Vitamin B(12) Interactions.

Castillo LF, Pelletier CM, Heyden KE, Field MS · Annual review of nutrition · 2025

Folate and vitamin B12 (B12) are essential cofactors in folate-mediated one-carbon metabolism (FOCM). FOCM includes a series of methyl transfer reactions for methionine regeneration and de novo synthesis of nucleotides, including thymidylate. Deficiency in either folate or B12 can result in negative health outcomes including megaloblastic anemia, with additional neurocognitive impairments observed as a result of B12 deficiency. While folate deficiency is not common in the United States due to mandatory folic acid fortification, B12 deficiency is observed more frequently, particularly in certain subpopulations such as vegetarians/vegans and older adults. Fortification of the food supply with folic acid has been effective to increase folate status and reduce the incidence of birth defects. However, consumption of fortified foods and use of dietary supplements containing folic acid have led to an increase in the proportion of individuals exceeding the tolerable upper intake level of folic

Vitamin B12 Deficiency: Common Questions and Answers.

Patel H, McGuirk R · American family physician · 2025

Vitamin B12 deficiency occurs in approximately 2% to 3% of adults in the United States. Risk factors include malabsorptive processes, limited dietary intake of vitamin B12, use of certain medications (eg, metformin, proton pump inhibitors), and older age. Symptoms vary based on the severity of vitamin B12 deficiency but may include fatigue, brain fog, depression, peripheral neuropathy, and ataxia. Although universal screening is not recommended, testing should be considered in patients with at least one risk factor for and one clinical feature of vitamin B12 deficiency. Initial testing includes total serum vitamin B12 level, which is diagnostic for deficiency if less than 180 pg/mL. Borderline levels (180-350 pg/mL) warrant a methylmalonic acid measurement, which is diagnostic for vitamin B12 deficiency if elevated. Patients without a clear cause of deficiency should undergo further testing for atrophic gastritis with a Helicobacter pylori test and evaluation for autoantibodies associa

A Pilot Study of Vitamin K2 (Menaquinone-7, Soloways ™) in Patients With Osteopenia/Osteoporosis Carrying a VDR Gene Variant

n=40 · NCT06867952 · RECRUITING · RECRUITING

This pilot, genotype-stratified clinical trial aims to evaluate the safety and preliminary efficacy of vitamin K2 (menaquinone-7, MK-7) supplementation in patients with low bone mineral density (osteopenia or osteoporosis) who carry a specific "unfavorable" variant in the vitamin D receptor (VDR) gene (e.g., BsmI or ApaI polymorphisms). The trial will compare improvements in bone health and related biomarkers between two cohorts: (1) homozygous carriers of the VDR variant and (2) non-variant carriers (wild-type). Investigators hypothesize that MK-7 supplementation will lead to greater improvements in bone mineral density (BMD) and bone turnover markers in the homozygous variant group due to their potentially reduced baseline response to vitamin D signaling.