Both prescribed and over-the-counter medications can interact with the nutrients in foods and drinks, such as calcium, potassium, sodium, and other vitamins, and herbal supplements. Interactions happen when one or more nutrient affects the manner in which a medication works. Conversely, a medication may impact the intended effect of a nutrient or herb.
Interactions can be beneficial or harmful – that is, they can produce positive or negative effects on our bodies. For example, a positive interaction occurs when an individual takes omega-3 fatty acid supplements (such as fish oil) with citalopram (an antidepressant). This combination may increase the medications’ effectiveness. However, a negative interaction may occur when Vitamin K is taken with warfarin, a blood thinner medication. Vitamin K is known to antagonize this blood thinner. This means that it makes the blood clot more slowly. Vitamin K is commonly found in multivitamins and in foods such as leafy green vegetables. Individuals taking warfarin must closely monitor their daily intake of Vitamin K.
There are some medications that work better when taken with food, while others may work best when taken on an empty stomach. And there are other medications that cannot be taken with specific foods or drinks due to a risk of severe side effects. For example, antidepressant medication taken with alcohol is extremely risky because it can alter the way the body metabolizes (breaks down) the medication.
How do you know if you are having a medication-nutrient-herb interaction?
The symptoms of medication-nutrient-herb interactions vary greatly and range from mild to very serious. Some common signs include feeling ill, fatigued, or energetic after taking a medication, or not getting the usual results from a medication.
You can download a table containing a list of possible medication-nutrient-herb interactions for some of the most commonly prescribed medications here:
This table also provides tips on how to manage them. It is important to note that not all interactions are covered in this table. Talk with your pharmacist and read the detailed printed information about your medications to determine possible food or herbal supplements interaction with medications you are currently taking.