Each Vcap contains: Vitamin K (K2, as menaquinone) 100 mcg • Alfalfa (medicago sativa) 300 mg. Other Ingredients: Rice flour, Cellulose (capsule), Maltodextrin, Magnesium Stearate (vegetable source), Silica.
Brand name products often contain multiple ingredients. To read detailed information about each ingredient, click on the link for the individual ingredient shown above.
Below is general information about the effectiveness of the known ingredients contained in the product Vitamin K2. Some ingredients may not be listed. This information does NOT represent a recommendation for or a test of this specific product as a whole.
INSUFFICIENT RELIABLE EVIDENCE to RATE
INSUFFICIENT RELIABLE EVIDENCE to RATE
Below is general information about the safety of the known ingredients contained in the product Vitamin K2. Some ingredients may not be listed. This information does NOT represent a recommendation for or a test of this specific product as a whole.
POSSIBLY SAFE ...when the leaves are used orally and appropriately, short-term (4,6,12).
LIKELY UNSAFE ...when large amounts are used long-term. Chronic ingestion of alfalfa has been associated with drug-induced lupus effects (381,14828,30602).
PREGNANCY AND LACTATION: POSSIBLY UNSAFE
when used orally in medicinal amounts.
Alfalfa contains constituents with possible estrogenic activity (4,11,30592).
LIKELY SAFE ...when vitamin K1 (phytonadione) or vitamin K2 (menaquinone) is used orally and appropriately. Vitamin K1 up to 10 mg daily and vitamin K2 up to 45 mg daily have been safely used in clinical trials lasting up to 2 years. A tolerable upper intake level for vitamin K in adults has not been set (54,55,58,6799,7135,14364). ...when vitamin K1 (phytonadione) is used parenterally and appropriately. Vitamin K1 (phytonadione) in oral and injectable form is an FDA-approved drug (7135).
POSSIBLY SAFE ...when vitamin K1 (phytonadione) 0. 1% is used topically in a cream or ointment for up to 12 weeks (91455,103919).
CHILDREN: LIKELY SAFE
when vitamin K1 (phytonadione) is used orally or parenterally and appropriately.
Vitamin K1 (phytonadione) in oral and injectable form is FDA approved for use in children. A tolerable upper intake level for vitamin K in children has not been set (7135).
PREGNANCY AND LACTATION: LIKELY SAFE
when used orally in amounts that do not exceed the daily adequate intake level (AI).
A tolerable upper intake level for vitamin K in pregnancy and lactation has not been set (7135).
Below is general information about the interactions of the known ingredients contained in the product Vitamin K2. Some ingredients may not be listed. This information does NOT represent a recommendation for or a test of this specific product as a whole.
Theoretically, alfalfa might increase the risk of hypoglycemia when taken with antidiabetes drugs.
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Theoretically, alfalfa might interfere with the activity of contraceptive drugs.
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Theoretically, alfalfa might interfere with hormone therapy.
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Theoretically, alfalfa might decrease the efficacy of immunosuppressive therapy.
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Theoretically, concomitant use of alfalfa with photosensitizing drugs might have additive effects.
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Animal research suggests that excessive doses of alfalfa may increase photosensitivity, possibly due to its chlorophyll content (106043). It is unclear if this effect would be clinically relevant in humans.
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Theoretically, alfalfa might reduce the anticoagulant activity of warfarin.
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Vitamin K can antagonize and reverse the therapeutic effects of warfarin.
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Below is general information about the adverse effects of the known ingredients contained in the product Vitamin K2. Some ingredients may not be listed. This information does NOT represent a recommendation for or a test of this specific product as a whole.
General
...Orally, alfalfa leaf seems to be well tolerated.
However, a thorough evaluation of safety outcomes has not been conducted.
Most Common Adverse Effects:
Orally: Abdominal discomfort, diarrhea, and flatulence.
Serious Adverse Effects (Rare):
Orally: Lupus-like syndrome after chronic ingestion of alfalfa.
Dermatologic ...Dermatitis associated with alfalfa use has been reported. In a 1954 publication, dermatitis was noted in a 61-year-old female consuming 4-6 cups of tea made with two tablespoonfuls of alfalfa seeds for approximately two months prior to onset. Examination revealed diffuse, confluent edema and erythema on the face, eyelids, ears, hands, forearms, and distal humeral regions. The dermatitis improved with treatment; re-exposure to alfalfa resulted in a similar reaction (30609).
Endocrine
...Alfalfa contains constituents, including coumestrol, with reported estrogenic activity (30586,30592,4753).
Effects in humans are not known.
One case report documents hypokalemia in a female who had been drinking a "cleansing tea" containing alfalfa, licorice, and stinging nettle. The potassium level returned to normal after discontinuing the tea and initiating potassium supplementation. The specific cause of the hypokalemia is not clear. Notably, both stinging nettle and licorice have been associated with hypokalemia and may have been responsible for this effect (30562).
Gastrointestinal ...Orally, flatulence and bulkier feces were reported during the first week of a case series of three subjects ingesting alfalfa (30598). In a case series of 15 patients ingesting alfalfa, increased fecal volume and increased stool frequency was reported. Additional adverse effects included abdominal discomfort in two patients, diarrhea in two patients, loose stools in six patients, and intestinal gas in 13 patients (5816).
Hematologic ...Pancytopenia and splenomegaly were reported in a 59-year-old male who had been taking 80-160 grams of ground alfalfa seeds for up to six weeks at a time, for a five month period. Hematologic values and spleen size returned to normal when alfalfa was discontinued (381).
Other
...Alfalfa products, including sprouts, seeds, and tablets, have been found to be contaminated with Escherichia coli, Salmonella, and Listeria monocytogenes, which have caused documented infections (5600,30566,30568,30572,30569,30564,30604,30610,30563,30607) (30566,30564,30604,30610,30563,30607,30576).
Orally, alfalfa has been associated with the development of a lupus-like syndrome in animals and humans (30594,14828,14830,30602), as well as with possible exacerbations of lupus in patients with known systemic lupus erythematosus (SLE). These reactions may be associated with the amino acid L-canavanine (30594), which appears to be present in alfalfa seeds and sprouts, but not leaves, and therefore should not be present in alfalfa tablets manufactured from the leaves (30601). However, case reports have included individuals ingesting tablets. A lupus-like syndrome was described in four patients taking 12-24 alfalfa tablets per day. Symptoms included arthralgias, myalgias, and rash; positive antinuclear antibodies (ANA) arose anywhere from three weeks to seven months after initiating alfalfa therapy. Upon discontinuation of alfalfa tablets, all four patients became asymptomatic. In two patients, ANA levels normalized (14828). Two additional reports have documented possible exacerbation or induction of SLE associated with alfalfa use. One case involved a female with a 26-year history of SLE, who had been taking 15 tablets of alfalfa daily for nine months prior to an exacerbation. Because of the delay in onset of the exacerbation from the initiation of alfalfa therapy, causation cannot be clearly established (30575). In a different report, SLE and arthritis were found in multiple family members who had been taking a combination of vitamin E and alfalfa tablets for seven years (30602). It is not known what other environmental or genetic factors may have affected these individuals, and the association with alfalfa is unclear.
General
...Orally, vitamin K is generally well tolerated.
Most Common Adverse Effects:
Orally: Diarrhea, nausea, and stomach upset.
Serious Adverse Effects (Rare):
Intravenously: There have been rare cases of anaphylaxis and hyperbilirubinemia (in infants).
Dermatologic ...Orally, intake of vitamin K2 (menaquinone) along with calcium and vitamin D3 can cause an increased incidence of skin and skin appendage lesions compared to taking calcium and vitamin D3 alone. However, the risk of this adverse event is low, with 0.5 incidences per 100 patient-years occurring for patients treated with vitamin K, calcium, and vitamin D3 and 0.1 incidences per 100 patient-years occurring for patients treated with calcium and vitamin D3 alone (85467).
Gastrointestinal ...Orally, vitamin K can cause mild to moderate gastrointestinal side effects (91450,91451). The most common effects include nausea, abdominal pain, and diarrhea (91450,91451).
Hepatic ...Orally, vitamin K3 (menadione) has been linked to hepatotoxicity. Vitamin K3 is no longer used therapeutically in North America because it has been linked to hepatic toxicity and jaundice in animal research (7135).
Other ...Intravenously, vitamin K can cause reactions that resemble hypersensitivity or anaphylaxis (85389). These reactions are rare. It is unclear whether the adverse effect is caused by the drug or a component of the solution. There have been very rare cases of hyperbilirubinemia, particularly in premature neonates, following large doses of vitamin K (15).
