What vitamins should I take while on GLP-1? A guide to nutritional support

October 15, 2025 •

4 min read

Research shows that many GLP-1 users experience reduced nutrient intake due to decreased appetite and altered digestion. To counteract this and support your weight loss journey, it is important to understand what vitamins should I take while on GLP-1 to prevent deficiencies and manage side effects.

Quick Summary

This article details potential nutrient deficiencies that can occur with GLP-1 medications and identifies key vitamins and supplements to consider. It provides guidance on prioritizing protein, managing common side effects with nutrition, and emphasizes the importance of consulting a healthcare provider.

Key Points

A Daily Multivitamin is Recommended: Taking a daily multivitamin can help fill potential nutritional gaps that result from reduced food intake while on GLP-1 medications.
Monitor Key Nutrients: Pay attention to your intake of Vitamin B12, Vitamin D, Calcium, Iron, and Magnesium, as deficiencies are common among GLP-1 users.
Prioritize Protein: Aim for adequate protein intake to prevent muscle mass loss during weight reduction; shakes can be a helpful supplement.
Manage Side Effects with Supplements: Ginger can help alleviate nausea, while fiber and probiotics can address constipation.
Stay Hydrated and Consider Electrolytes: Reduced thirst and side effects like vomiting can cause dehydration, so adequate fluid and electrolyte intake is critical.
Consult a Healthcare Provider: Always speak with your doctor or a dietitian before starting any new vitamin or supplement, as needs vary individually.

Why GLP-1 Medications Impact Nutrient Absorption

Glucagon-like peptide-1 (GLP-1) receptor agonists, such as semaglutide (Ozempic, Wegovy) and tirzepatide (Mounjaro, Zepbound), are highly effective for managing diabetes and promoting weight loss. They work by mimicking a natural hormone to slow gastric emptying, suppress appetite, and increase feelings of fullness. While these effects are beneficial for weight management, they can also lead to unintended nutritional consequences. Key mechanisms include:

Reduced Food Intake: A suppressed appetite often means eating less, and fewer calories can lead to a lower intake of essential vitamins and minerals.
Slower Digestion: By delaying the movement of food through the stomach, GLP-1s can affect how efficiently your body absorbs nutrients.
Gastrointestinal Side Effects: Nausea, vomiting, and diarrhea—common side effects, especially during the initial phases of treatment—can further hinder nutrient absorption.

Key Nutrients to Monitor on GLP-1s

Reduced intake and altered digestion can make you more susceptible to deficiencies in several crucial nutrients. Based on recent studies and expert consensus, the following are the most important to monitor and potentially supplement:

A Daily Multivitamin: Your Foundational Support

For many GLP-1 users, taking a daily multivitamin is an excellent starting point to cover a wide range of potential nutrient gaps. A good quality multivitamin can provide a foundational level of support for essential micronutrients, especially when calorie intake is restricted. Always choose a high-quality product and consult your doctor before starting any new supplement regimen.

Individual Supplements for Targeted Needs

While a multivitamin is a good baseline, some individuals may need additional, targeted support based on their specific diet, health status, and blood test results. Here are some key supplements to discuss with your healthcare provider:

Vitamin B12: Essential for energy production and nerve function, B12 deficiency can be a particular concern, especially for those also taking metformin, a medication known to interfere with its absorption. GLP-1s themselves might also impact B12 status.
Vitamin D: Often found to be deficient in individuals with obesity and those on low-calorie diets, Vitamin D is crucial for bone health and immune function.
Calcium: During significant weight loss, there is a risk of decreased bone mineral density. Pairing calcium with Vitamin D can help support bone strength.
Iron: Reduced appetite and changes in food preferences can lead to low iron intake, potentially causing fatigue and weakness. Monitoring iron levels is especially important for women of childbearing age and vegetarians.
Magnesium: Involved in hundreds of bodily processes, magnesium deficiencies are common even without medication. It can support nerve and muscle function and help regulate blood sugar.
Omega-3 Fatty Acids: Often found in fish oil supplements, omega-3s can support heart health and reduce inflammation.

Nutritional Strategies for Managing Side Effects

Supplements can also help manage the gastrointestinal side effects associated with GLP-1 medications:

Nausea: Many users experience nausea, particularly when starting or increasing doses. Ginger, available in supplements or as a tea, can be highly effective in soothing an upset stomach.
Constipation: Slowed digestion can lead to constipation. Fiber supplements, such as psyllium husk, can promote regularity, and probiotics may support overall gut health and digestive comfort.
Dehydration: Suppressed thirst is a side effect for some users. Electrolyte solutions can help maintain proper hydration, especially if you experience vomiting.

Prioritizing Protein to Preserve Muscle Mass

Rapid weight loss on GLP-1s can lead to the loss of both fat and muscle mass. To preserve muscle, adequate protein intake is essential. While focusing on lean protein sources in your diet is the primary goal, a protein powder or shake can be a convenient way to meet your daily needs, especially if you have a low appetite. Experts recommend aiming for about 0.8 to 1.2 grams of protein per kilogram of body weight per day.

Comparing Supplement Strategies for GLP-1 Users


Feature	Foundational Multivitamin Plan	Targeted Supplementation Plan
Recommended For	Most GLP-1 users looking for general nutrient support.	Individuals with confirmed deficiencies or specific side effects.
Main Supplements	High-quality daily multivitamin.	Daily multivitamin + specific supplements like B12, Vitamin D, iron, or magnesium, based on blood work.
Additional Support	May add protein shakes and fiber/probiotics for side effects.	Protein shakes, fiber, probiotics, omega-3s, and ginger for nausea management.
Provider Guidance	Basic consultation is recommended.	Requires more active involvement with a healthcare provider and possibly a dietitian.
Pros	Simple, cost-effective, covers most common gaps.	Personalized, addresses specific issues, potentially more effective for deficiencies.
Cons	May not provide sufficient amounts for severe deficiencies.	More expensive, requires blood testing, and more complex to manage.

Consult Your Healthcare Provider

Before adding any vitamins or supplements to your regimen, it is crucial to speak with your healthcare provider or a registered dietitian. They can assess your individual needs based on your diet, health status, and medication. Blood tests can help identify specific deficiencies, allowing for a personalized and targeted supplementation plan. This professional guidance ensures that you address your nutritional needs safely and effectively while maximizing the benefits of your GLP-1 medication. A great resource for dietary guidance is the Ohio State Health & Discovery website, which offers tips on balancing nutrition on GLP-1s.

Conclusion

GLP-1 medications are a powerful tool for health improvement, but they require a proactive approach to nutrition. By understanding the potential for nutrient deficiencies and focusing on a well-rounded diet supplemented with key vitamins like B12 and D, along with adequate protein, users can mitigate risks and support their well-being. A daily multivitamin provides a solid foundation, while targeted supplements can address specific issues. Always partner with a healthcare professional to tailor a plan that's right for you, ensuring a safe and successful journey towards your health goals.

Frequently Asked Questions

Yes, for most people it is safe to take supplements with GLP-1 medications, but it is important to consult your healthcare provider first. They can help determine your specific needs and ensure there are no interactions.

GLP-1 medications like Ozempic and Wegovy can lead to reduced food intake and slower digestion, which may result in lower levels of essential vitamins and minerals if not properly addressed through diet or supplements.

A daily multivitamin is often recommended as a simple way to help fill potential nutrient gaps when your caloric and food intake is reduced. It provides a baseline of support for overall health.

There is evidence suggesting that GLP-1 medications might contribute to B12 deficiency, especially if combined with other medications like metformin. It is wise to have your B12 levels monitored.

Ginger supplements, lozenges, or tea can be effective for managing nausea, a common side effect of GLP-1 medications, particularly when starting treatment.

Focus on incorporating lean protein sources in smaller, more frequent meals. If you have a suppressed appetite, a protein shake can be an easy and effective way to ensure you meet your daily protein targets.

Staying well-hydrated is key to preventing constipation. Additionally, increasing your fiber intake through food or a psyllium-based fiber supplement and considering a probiotic can be helpful.