GLP-1 medications like semaglutide and tirzepatide have become increasingly common in conversations around weight loss. As their use grows, so does our understanding of what comes along with them.

One area that deserves more attention is nutrient depletion.

This isn’t something new. In oncology, we’ve seen for years that when people eat less—whether from chemotherapy, stress, or a loss of appetite—the body can become depleted in key nutrients.
We’re now seeing a similar pattern with GLP-1–associated weight loss, where reduced intake can lead to nutritional gaps over time.

Especially for cancer patients who are also taking GLP-1 medications, this is something that requires careful attention. Supporting the body with the right nutrients is a foundational part of long-term health.

Why This Happens

GLP-1 medications reduce appetite, help people feel full faster, and often lead to smaller portions or skipped meals.

Over time, this can create a simple but important shift: less variety of food coming in means fewer nutrients available to the body.

In some cases, people also begin to avoid certain foods, including proteins or raw vegetables, because they feel harder to tolerate. This can further narrow the range of nutrients the body receives.

In addition, these medications slow digestion, which can contribute to changes in gut absorption: meaning the body may not absorb nutrients as efficiently as before.

Taken together, reduced intake and altered absorption can increase the risk of malnutrition, even while weight loss is occurring.

Research now suggests that up to 22% of individuals may develop at least one nutrient deficiency within a year if these gaps aren’t addressed (ScienceDirect, 2025).

The Most Common Nutrient Gaps (and What to Do About Them)

Vitamins

Vitamin D

• Why it matters: Bone strength, immune support, mood
• Foods: Fatty fish, egg yolks, fortified dairy, sunlight
• What to do: Monitor levels and ensure consistent intake

B Vitamins (B12 & Folate)

• Why they matter: Energy, brain function, red blood cells
• Foods: Meat, fish, eggs, dairy, leafy greens, beans
• What to do: Prioritize protein and plant diversity

Vitamin C

• Why it matters: Immune support, antioxidant function
• Foods: Citrus, berries, bell peppers
• What to do: Include daily fruits/vegetables

Minerals

Calcium

• Why it matters: Bone health
• Foods: Dairy, leafy greens, almonds
• What to do: Maintain consistent intake

Iron

• Why it matters: Energy, oxygen transport
• Foods: Red meat, spinach, lentils
• What to do: Pair with vitamin C for absorption

Magnesium

• Why it matters: Sleep, muscle function
• Foods: Nuts, seeds, dark chocolate
• What to do: Be intentional with intake

Zinc

• Why it matters: Immune support, healing
• Foods: Meat, shellfish, seeds
• What to do: Maintain adequate protein intake

Potassium

• Why it matters: Heart and muscle function
• Foods: Bananas, avocados, potatoes, beans
• What to do: Keep fruits and vegetables consistent

Protein (Most Overlooked)

• Why it matters: Muscle preservation, metabolism
• Foods: Meat, fish, eggs, yogurt, legumes
• What to do: Prioritize at every meal

Food First: But Not Always Food Alone

Whenever possible, it is best to meet nutritional needs through whole foods.

However, when intake is reduced—or when rebuilding after depletion—high-quality supplementation can be an effective way to help fill nutritional gaps.

The goal is not to replace food, but to support the body where needed.

In practice, many people find that maintaining this level of consistency through food alone can be challenging: especially when appetite is reduced. This is where thoughtfully designed supplement routines can play a supportive role.

At SurvivorRx, our approach has always been centered around filling common nutritional gaps with transparency, appropriate dosing, and high-quality ingredients, especially during times when the body may need additional support.

The Bottom Line

GLP-1 medications change more than appetite: they change nutrient intake and absorption.

• Eat less—but eat with intention
• Focus on nutrient-dense foods
• Maintain protein and variety
• Address gaps early

Because long-term health isn’t just about weight; it’s about what your body still has access to along the way.

References

• ScienceDirect: Nutritional deficiencies in GLP-1 users (2025)
  https://www.sciencedirect.com/science/article/pii/S2667368125000300
• Verywell Health: GLP-1 medications and vitamin deficiencies (2025)
  https://www.verywellhealth.com/glp-1-and-vitamin-d-deficiency-11922920
• Healthline: GLP-1 drugs and vitamin C deficiency cases (2025)
  https://www.healthline.com/health-news/glp1-drugs-develop-scurvy
• Frontiers in Nutrition: Effects of GLP-1 therapies on dietary intake (2025)
  https://www.frontiersin.org/articles/10.3389/fnut.2025.1566498/full