Menaquin

Indications

Menaquinone-7 (MK-7) is a natural form of vitamin K2, found in fermented foods such as natto. It is used as a supplement, usually together with Calcium and Vitamin D3, to support bone health, help prevent and manage osteoporosis (thin, weak bones), and support healthy blood vessels by helping calcium go into bones rather than artery walls. It is also used to correct vitamin K deficiency.

How It Works

Vitamin K2 switches on certain proteins in the body. One, osteocalcin, helps bind calcium into the bone structure, improving bone strength. Another, matrix Gla protein, helps stop calcium from building up in blood vessels and soft tissues. Vitamin K is also needed for the liver to make clotting factors that stop bleeding. The MK-7 form stays in the blood longer than other forms, so it works well with once-daily dosing.

Dosage and Administration

Adults: commonly 45 to 180 micrograms (mcg) once daily, usually 90 to 100 mcg, with a meal that contains some fat for better absorption, or as directed on the label or by your doctor. In combination products the dose is set by the product.

Interactions

• Vitamin K can reduce the effect of Warfarin and other vitamin K antagonist blood thinners, increasing the risk of clots. Do not take MK-7 with these medicines unless your doctor agrees and monitors your INR.
• Orlistat, bile acid binders such as Cholestyramine and mineral oil can reduce its absorption.
• Long courses of broad-spectrum antibiotics can lower vitamin K levels.

Contraindications

• Allergy to any ingredient (some products are made from soy)
• People taking Warfarin or Acenocoumarol, unless specifically advised by their doctor

Side Effects

Usually very well tolerated at normal doses. Possible effects include:

• Mild stomach upset or nausea
• Bloating or diarrhoea
• Rarely, skin rash

Get urgent medical help if you take a blood thinner and notice signs of a clot, such as a painful swollen leg, sudden chest pain, breathlessness, or sudden weakness of the face or limbs, or if you have signs of a serious allergic reaction such as swelling of the face or difficulty breathing.

Pregnancy and Lactation

Vitamin K is a normal part of the diet, but there is limited information on MK-7 supplements in pregnancy and breastfeeding. Use only if your doctor recommends it.

Precautions and Warnings

• Tell your doctor before starting if you have a bleeding or clotting disorder or take any blood thinner.
• People with liver disease or fat malabsorption may need medical advice on dosing.
• A supplement supports, but does not replace, prescribed osteoporosis treatment, exercise and a balanced diet.

Overdose

Vitamin K2 has low toxicity and overdose is unlikely to cause serious harm in people not taking blood thinners. If a large amount is taken, or if you take Warfarin, contact a doctor.

Therapeutic Class

Vitamin K2 supplement, bone health agent

Storage

Store below 30°C in a dry place, away from light and out of the reach of children.