Functional medicine practitioners favor treating patients with dietary and lifestyle interventions first and turning to pharmaceutical drugs only when absolutely necessary. As powerful as diet and lifestyle are, though, there are cases in which drugs do play a role, or where they can be a bridge to help a patient manage a condition while they transition to a healthier diet and lifestyle. In cases where pharmaceutical drugs are an appropriate option, patients should be made aware of the mechanisms by which their medications work, and what the implications are for micronutrient status. Far too many patients under the conventional medical approach are handed a prescription and sent on their way with no knowledge of how the drugs work and what the potential consequences and side-effects are.

One drug-nutrient interaction that is well recognized is the reduction in CoQ10 synthesis from statin drugs. Statins act on the mevalonate pathway by inhibiting the enzyme HMG CoA reductase. Cholesterol and ubiquinone are produced at the very end of this pathway, but HMG CoA reductase is a relatively early step, so inhibiting this enzyme reduces biosynthesis of everything that comes after, not just cholesterol. (Specialized proteins in pancreatic beta cells involved in insulin secretion are also affected by statins, which may explain in part the increased risk for type 2 diabetes noted with statin use.)

But that’s only one class of drugs among a huge array of others. Antacids interfere with proper mineral absorption, which likely explains the noted association between use of proton pump inhibitors and increased risk for bone fracture. Because of impaired vitamin and mineral absorption, long-term antacid use has also been associated with increased risk for dementia. Among several other micronutrients, B12 is essential for healthy cognitive function, and antacids are known to impair B12 absorption. Metformin is another widely prescribed drug that may result in reduced B12 absorption, with deficiency even progressing to the point of potentially causing permanent neuropathy.

Another class of cholesterol-lowering medications, the bile acid sequestrants (e.g., cholestyramine, cholestipol), presents a different set of nutritional challenges. Owing to their role in increasing excretion and elimination of bile, these drugs reduce absorption of fat-soluble vitamins, including vitamins A, D, E, and K, as well as beta-carotene and other fat-soluble nutrients.    

Corticosteroids, which some patients might not be able to imagine life without, don’t just ameliorate pain. In addition to their well-known potential for inducing weight gain, oral corticosteroids also increase urinary excretion of vitamins C and B6, potassium, selenium and zinc.

Patients might be more motivated to make necessary diet and lifestyle changes if they were better informed of the potentially dangerous effects of long-term use of various drugs. Additionally, it may be helpful to note that in many cases, these issues are not “side effects,” but rather, are predictable results of the mechanisms by which the drugs work. For example, if proton pump inhibitors inhibit secretion of hydrochloric acid, there’s little reason to suspect these drugs wouldn’t impact mineral absorption.

In an ideal world, no one would need drugs at all, but there are certainly times when use is warranted and perhaps even essential. When it’s clinically appropriate for certain drugs to be used while a patient transitions to a healthier diet and lifestyle, they can be guided toward effective supplementation with a goal of minimizing the potential adverse effects of the drugs on nutrient absorption and/or retention.

Owing to the various mechanisms by which pharmaceutical drugs exert their effects, there’s a wide array of drug categories to explore and certainly no shortage of information to be learned in order to better serve patients. We’ll have more articles in the future taking a closer look at specific drugs, the effects they have on nutrient absorption or excretion, and the potential health consequences of this.