by Angela Halderson
The use of GLP-1 receptor agonists — such as semaglutide (Wegovy, Ozempic), liraglutide (Victoza, Saxenda), and tirzepatide (Zepbound, Mounjaro) — has rapidly increased due to their effectiveness in promoting weight loss and improving blood sugar control. These medications work primarily by suppressing appetite, curbing cravings, and slowing gastric emptying, helping individuals feel full sooner and eat less. However, emerging research suggests that these same effects may increase the risk of nutritional deficiencies, making intentional nutrition strategies essential for those using these therapies.
A recent review published in Clinical Obesity examined data from nearly 500,000 adults and found several notable trends. More than 60% of participants consumed inadequate amounts of calcium and iron, while deficiencies in vitamins B1 and B12 increased over time. Vitamin D deficiency affected 7.5% of participants at six months and 13.6% at one year. Iron status was also impacted, with ferritin levels significantly lower compared with individuals using other diabetes medications. The review also noted that 30–40% of weight lost on GLP-1 medications may come from lean muscle mass, often due in part to insufficient protein intake.
To counteract these risks, individuals taking GLP-1 medications should prioritize protein intake. Protein is critical for preserving muscle mass, maintaining metabolism, and supporting overall health. A general target is 1.2–1.5 grams of protein per kilogram of adjusted body weight per day, though individual needs may vary. Because appetite is often reduced, it can help to focus on protein-rich foods first at meals. Convenient, nutrient-dense options include eggs, Greek yogurt, cottage cheese, lean meats, fish, tofu, beans, and protein shakes.
Micronutrient intake is equally important. A daily multivitamin can help fill common nutritional gaps, especially one that includes B vitamins, such as B1 and B12, and vitamin D. Adding nutritional yeast to meals can be a natural and tasty way to help reach B vitamin goals. These nutrients are essential for energy production, nerve function, and bone health, and may be more difficult to obtain in adequate amounts when overall food intake is reduced.
Vitamin D deserves particular attention due to its high rate of deficiency. Many adults benefit from supplementation in the range of 1,000–2,000 IU daily, although individual needs should ideally be guided by lab testing and healthcare provider recommendations.
Calcium intake should also be emphasized, preferably through food sources. Dairy products like milk, yogurt, and cheese are rich in calcium, as are fortified plant-based milks, leafy green vegetables such as kale, almonds, and calcium-set tofu. Adults generally need 1,000–1,200 milligrams of calcium per day to support bone health.
Lastly, regular monitoring can help identify deficiencies early. Periodic lab tests for vitamin D, B12, and iron levels can guide adjustments in diet and supplementation.
While GLP-1 medications are highly effective, they are not without nutritional considerations. By focusing on adequate protein intake, incorporating nutrient-dense foods, and using appropriate supplementation, individuals can protect their health and maximize the benefits of their treatment.
Urbina J, Salinas-Ruiz LE, Valenciano C, Clapp B. Micronutrient and Nutritional Deficiencies Associated With GLP-1 Receptor Agonist Therapy: A Narrative Review. Clin Obes. 2026 Feb;16(1):e70070. doi: 10.1111/cob.70070. PMID: 41549912.
This article was originally published in the May 2026 issue of Appleton Monthly Magazine.
