Meal Replacement Drinks and Warfarin

By: Alere Staff

Meal replacement drinks were once considered only for hospitalized patients that were unable to swallow or refused meals. These beverages contained all the vitamins and minerals needed for the body to heal while being easier for the body to manage when sick. Today meal replacement drinks seem everywhere, promising a full meal in every bottle for people who are too busy to stop for a meal, looking for weight loss or want the extra nutrients for a workout. 

When taking warfarin, you should always be mindful of the ingredients that you are putting into your system, including drinks with extra vitamins and vitamin supplements like vitamin K. You should be aware that ingredients may interact with warfarin. Below is a list of some of the more common meal replacement drinks available and the amount of vitamin K present per serving.


Serving Size

Vitamin K1


Nestle BOOST® Original (chocolate flavor)

1 bottle (237 g.)

29.2 mcg.


Nutrisystem® Shake (milk chocolate)

1 bottle (325 ml.)

20.1 mcg.


SlimFast®, Meal Replacement Shake (creamy milk chocolate)

1 bottle (325 ml.)

20.1 mcg.


SlimFast®, Meal Replacement Shake Mix (creamy milk chocolate)

¼ cup (26 g.)

20.0 mcg.


Ensur Plus® Shake (chocolate flavor)

1 cup

19.9 mcg.


SlimFast® Meal Replacement, High Protein shake

1 bottle (295 g.)

19.2 mcg.


Kellogg’s Special K® Protein Shake

1 bottle (296 g.)

18.9 mcg.


Kellogg’s Breakfast To Go Shake (milk chocolate)

10 fl. oz.

6.5 mcg.


CalNaturale Svelte® Protein Shakes (Spiced Chai)

11 fl. oz.

Not measureable per serving.


Orgain® Organic Nutrition Shake (Strawberries and Cream)

11 fl. oz.

Not measureable per serving.


While it may be tempting to use meal replacement shakes often, it is good to be aware of the ingredients. As a patient on warfarin, you may look to the shakes because they either have smaller amounts of vitamin K or calories. However, when you compare a full meal with a meal replacement shake, you may find that you are not getting enough vitamin K in your diet as well as other vitamins, minerals, calories and proteins. For example, below are four different meal examples with their vitamin K content available on this website in the Café PTINR® section.



Vitamin K

Vitamin K Level

Mediterranean Chicken Salad


29 mcg.


Pork Tenderloin and White Bean Soup


28 mcg.


Salmon with Caper Mayonnaise and Wild Rice with Black Beans


26 mcg.



Pizza with Roasted Garlic and Tomato


24 mcg.


From the chart, you can see that the meal option with the highest vitamin K content contains about the same amount of vitamin K as the meal replacement drink with the highest vitamin K content. They both contain high vitamin K levels, but one of the main differences is the variety in ingredients between the salad and the shake. You may get the same vitamin K but not the same nutrients. The idea can be reversed as well. If you drink meal replacement drinks as well as your meals, you could be consuming too much vitamin K. Balance and consistency of vitamin K is important when managing your INR.

Other issues to be aware of with shakes intended as meal replacement choices is that they may contain too much sugar and not enough protein, fat or fiber to stand in for what you may require. When looking at different recipes, make sure they do not contain lots of sugar and the ingredients, like fats, are taken from healthy sources like avocado, fish oil, olive oil or nuts.2  A good meal replacement drink is fine every once in a while, but there is no supplement that can take the place of a nutritious meal.3 A trick to making sure you get all your body needs can be planning ahead. If you do wish to use a meal replacement shake, speak with your physician about which one will be the right match for you and your INR.


  1. US Department of Agriculture, Agricultural Research Service, Nutrient Data Laboratory. USDA National Nutrient Database for Standard Reference, Release 28. Version Current:  September 2015, slightly revised May 2016.  Internet:  /nea/bhnrc/ndl
  2. Brabaw, K. The 7 Best Meal Replacement Shakes and Smoothies. Prevention. December 11, 2015.
  3. Zelman, K. M., MPH, RD, LD. Meal Replacements: Choose Those Bars and Drinks Carefully. WebMD. 2003.

Ensure is a trademark of Abbott Laboratories. BOOST is a trademark of Nestlé HealthCare Nutrition. Special K is a trademark of the Kellogg Company. SlimFast is a trademark of the SlimFast Company. Nutrisystem is a trademark of Nutri/System IPHC, Inc. Svelte is a trademark of the CalNaturale Company. Organic is a trademark of Orgain, Inc. Alere is not affiliated or associated with the noted trademark owners or their related trademarks.