Hi and welcome to the forum.
I do hope that someone can share their own personal experiences of what vitamins and supplements to take while taking warfarin. However if they do i personally think you should seek professional guidance because although this forum is full of useful information, advice and support, any advice given is through peoples own experiences and findings and what maybe right for one may not be right for another.
I would consult your wife's doctor/PD Nurse/Neurologist/pharmacist for professional guidance and your own piece of mind and safety.
We have a member called 'chewyexpert' who maybe able to offer you further advice if you would like to personal message him i'm sure he'd be able to give you some more information, but even so and i'm sure chewy would say this, still check with your health care professional before introducing any vitamins or supplements.
However, i did come across the following advice about what to avoid while taking warfarin....
What should I avoid while taking warfarin?
You should not take acetaminophen (Tylenol), aspirin, or NSAIDs (non-steroidal anti-inflammatory drugs) unless your doctor has told you to. NSAIDs include celecoxib (Celebrex), diclofenac (Voltaren), ibuprofen (Motrin, Advil), indomethacin, naproxen (Aleve, Naprosyn), piroxicam (Feldene), and others.These medicines may affect blood clotting and could cause serious bleeding in your stomach or intestines.
Avoid sudden changes in your diet. Vitamin K decreases the effects of warfarin. Large amounts of vitamin K are found in foods such as liver, broccoli, brussels sprouts, spinach, Swiss chard, coriander, collards, cabbage, and other green leafy vegetables. Do not change the amount of these foods in your diet without first talking to your doctor.
Avoid eating cranberries, drinking cranberry juice, or taking cranberry herbal products.
Avoid drinking alcohol, which can increase some of the side effects of this medication.
Avoid sports or activities that could result in a bruising or bleeding injury. Use extra caution to avoid cuts when brushing your teeth or shaving.
What are the possible side effects of warfarin?
Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Call your doctor at once if you have any of these serious side effects:
skin changes or discoloration anywhere on your body;
purple toes or fingers;
pain in your stomach, back, or sides;
low fever, loss of appetite, dark urine, jaundice (yellowing of the skin or eyes);
diarrhea, fever, chills, body aches, flu symptoms;
easy bruising or bleeding that will not stop;
blood in your urine;
black, bloody, or tarry stools;
nosebleeds, bleeding gums, coughing up blood;
feeling weak or light-headed;
sudden headache, confusion, problems with vision, speech, or balance;
sudden leg or foot pain; or
sudden numbness or weakness, especially on one side of the body.
Less serious side effects may include:
nausea, vomiting, stomach pain;
gas and bloating; or
This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect.
What other drugs will affect warfarin?
Warfarin interacts with many other drugs, and these interactions can be dangerous, even fatal. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor. Keep a list with you of all the medicines you use and show this list to any doctor or other healthcare provider who treats you.
Warfarin can interact with the following herbal (botanical) products:
St. John's wort.
Do not use any of these products without first asking your doctor. Some of these herbal products can cause you to bleed while you are also taking warfarin.
Where can I get more information?
Your pharmacist can provide more information about warfarin.
The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.