Optimize your nutrition on a GLP-1 by paying attention to these vitamins and minerals

Joanna Kriehn, MS, RDN, CDCES - Registered Dietitian Nutritionist and Certified Diabetes Care and Education Specialist (CDCES)

When taking GLP-1 medications (e.g., semaglutide/Ozempic/Wegovy, tirzepatide/Mounjaro/Zepbound), you are likely noticing you are eating less, so does that mean you're short on vitamins and minerals? Did you know that what you eat is just as important as how much? Maintain your health and stay on top of your nutrition by making an effort to include natural sources of these critical vitamins and minerals in your GLP-1 eating plan.

Why worry about vitamins and minerals when taking a GLP-1?

Vitamins and minerals are essential for converting food into energy, maintaining a healthy immune system, supporting bone health, and regulating hormone levels. GLP-1 medications, taken for weight loss or diabetes management, can significantly reduce appetite and, in some cases, food intake by as much as 16-39%. This fuel reduction, when on a GLP-1, can lead to an insufficient intake of essential vitamins and minerals.

Good news and bad news: GLP-1s don’t block nutrient absorption directly, so that's the good news. Instead, deficiencies can develop because of the following issues:

You feel full quickly and eat much smaller portions.
Nausea or food aversions limit variety.
Rapid weight loss increases nutrient needs.
Protein intake often drops unconsciously.
Fluid intake is reduced unintentionally.

Pro tip: Give yourself the best chance of meeting your vitamin and mineral needs when taking a GLP-1 by consuming enough energy each day. Strive for at least 1,200 calories/day (females), 1,500 calories/day (males). These dietitian-approved tips can help you manage common glp-1 side effects.

The most common vitamins and minerals at risk with GLP-1s

Protein (the foundation)

While not a vitamin or mineral, inadequate protein intake is a common issue and drives many downstream problems.

Why it’s at risk: A reduced appetite and eating smaller portions make it hard to meet daily protein needs. Additionally, some protein-rich foods may sound less appealing if you are experiencing nausea and vomiting.
Watch for: Muscle loss, fatigue, and hair thinning.
Strategy: Aim for 20-30 grams per meal, prioritizing protein first, or 80-100 grams per day, though exact protein needs will vary. If you can’t tolerate a full meal, strive for protein-rich snacks spaced throughout the day.

Favorite protein-rich recipe: Pan-Seared Scallops with Spinach

Scallops are rich in protein and omega-3 fatty acids, while spinach adds vitamins C, A, and K. Plus, this recipe is softer and easier to digest than some other protein-rich foods, such as beef.

Vitamin B12

B12 or cobalamin is essential for a variety of bodily functions, including making DNA and converting food into energy. It is also important for healthy nerve function.

Why it’s at risk: Smaller portions of animal foods; slowed digestion. Even higher risk if vegetarian, older adult.
Watch for: Fatigue, tingling, and brain fog.
Strategy: Include eggs, fish, dairy, or consider a low‑dose supplement.

Favorite B12-rich recipe: Tilapia with Lemon Sauce

This soft white fish cooks quickly and is easy to digest. Lemon adds some natural flavors for a weekend or weeknight dinner. Rich source of selenium, niacin, and vitamin B-12.

Iron

Iron is an essential mineral used to form hemoglobin, a protein in red blood cells that facilitates oxygen delivery. Iron is also vital for growth and development, as well as healthy hair.

Why it’s at risk: Reduced food intake.
Watch for: Fatigue, shortness of breath, hair shedding.
Higher risk if: Menstruating women, low-calorie diets.
Strategy: Include meat, seafood, legumes, and pair with vitamin C for enhanced absorption.

Favorite iron-rich recipe: Slow Cooker Chicken & Cannellini Stew

This prep-and-forget hearty stew cooks all day and is a great option for meal prepping. Rich in vitamins A, C, and K, along with dietary fiber.

Calcium & Vitamin D

Important for bone strength, muscle function, and immune health. Many adults fall short on these nutrients even before starting on a GLP-1.

Why they’re at risk: Reduced dairy intake. Vitamin D is a common deficiency.
Watch for: Muscle cramps, bone loss over time.
Strategy: Include fortified dairy or dairy alternatives; vitamin D often requires supplementation.

Favorite calcium and vitamin D-rich recipe: Overnight Oats with Chia Seeds and Raisins

This highly transportable meal or snack is filling and satisfying. Swap the raisins for almonds for some crunch and extra calcium. Rich in vitamin K, manganese, and vitamin B12.

Magnesium

Supports metabolism, energy use in the body, and muscle function.

Why it is at risk: Lower intake of whole grains, nuts, legumes
Watch for: Fatigue, muscle cramps.
Strategy: Include nuts, seeds, legumes, seafood, and soy products.

Favorite magnesium-rich recipe: Tofu & Spinach Stir-fry for Two

This quick weeknight stir-fry includes garlic, ginger, and sesame seeds with flavor-neutral tofu. Add additional veggies such as red bell peppers for a pop of color.

Rich in protein, calcium, magnesium, and vitamin A. Pairs well with cauliflower or brown rice.

Practical tips to prevent deficiencies

Think “protein first”
Eat protein before vegetables or starches. Even a few bites count.
Use small, nutrient-dense portions
You don’t need large meals—just strategic ones. Soft foods, soups, yogurt, eggs, tofu, and fish are often easiest to eat.
Consider a daily multivitamin
Select a multivitamin/mineral supplement to help fill nutritional gaps, especially during active weight loss.
Eat in mini‑intervals
On low‑appetite days, try 1 to 2 bites every 2 to 3 hours instead of full meals.
Monitor labs periodically
Ask your clinician about checking:
- Vitamin B12
- Ferritin (iron stores)
- Vitamin D
This is especially important if you’re over 50, menstruating, vegetarian, or losing weight rapidly.

Red flags needing further attention

Contact your healthcare team if you notice:

Difficulty eating and drinking at meals
Persistent fatigue or dizziness
Excessive hair loss
Numbness or tingling
Muscle weakness or
Poor wound healing.

GLP-1 medications can be powerful tools, but they work best when paired with intentional nutrition. You don’t need perfect eating, just consistently work to meet your vitamin and mineral needs.

With a protein‑forward approach, nutrient‑dense foods, and simple monitoring, most micronutrient deficiencies on GLP-1s are entirely preventable.

Optimize your nutrition on a GLP-1 by paying attention to these vitamins and minerals

Why worry about vitamins and minerals when taking a GLP-1?