Can Wegovy and Zepbound Cause Nutrition Deficiencies? (And What to do About It)]
The weight-loss medications Wegovyยฎ and Zepboundยฎ have changed the game for weight loss, but theyโre not without challenges.
As a Registered Dietitian, one question I hear often is: Can these medications lead to nutrition deficiencies? The short answer? Yes, they can. And itโs something worth paying attention to.
In this post, Iโll walk you through why these deficiencies happen, which nutrients are most often affected, andโmost importantlyโhow to stay nourished while losing weight.
Why You Can Develop Nutrition Deficiencies While Taking Weight Loss Meds
Why You Can Develop Nutrition Deficiencies While Taking Weight Loss Meds
f your BMI is 30 or higher, you might already have low levels of important nutrients before starting medication.
Research shows that people with a higher BMI are more likely to be low in nutrients like iron, calcium, magnesium, zinc, copper, folate, and vitamins A and B12.
Are You Eating Too Little?
GLP-1 medications like semaglutide and tirzepatide are highly effective at reducing appetite.
Many people go hours without eating and feel full quickly. While this is helpful for weight loss, eating too little can make it hard to get the nutrients your body needs.
Are You Eating Less, but Not Better?
Because these medications can lead to weight loss without big changes in diet, some people eat less but not better.
When your appetite is low, it’s more important than ever to choose nutrient-dense foods that provide your body what it needs for good health.
Common Nutrition Deficiencies in GLP-1 Users
New research shows that people on weight-loss medication can have vitamin and mineral deficiencies, particularly in the following. However, this is a list that we expect to grow as more research comes to light.
Vitamin D
A 2025 study found that the most common deficiency in people taking GLP-1 was vitamin D.ย
Recommendations:
Most adults need approximately 600-800 IU of vitamin D daily. But if you’re already low, your body may need more to catch up. This is often best accomplished with a supplement.
Signs of deficiency:
- Fatigue or low energy
- Mood changes (like depression)
- Trouble sleeping
- Hair loss
- Bone or joint pain
Food sources:
- Fatty fish (salmon, tuna, sardines)
- Egg yolks
- Fortified milk or dairy alternatives
Sunlight exposure is also a great source of vitamin D.
Iron
Iron deficiency is another common concern, and one that can leave you feeling drained.
Recommendations:
For most adult women under 50, the recommended daily intake of iron is 18 mg.ย After menopause, the recommendations drop to 8 mg per day, which is also the recommended amount for men.ย
Signs of deficiency:
- Low energy or fatigue
- Brittle nails
- Brain fog
- Irritability
- Hair thinning or hair loss
- Cravings for non-food items, like ice or dirt (a practice called pica)
Food sources:
- Red meat (e.g., beef and lamb)
- Poultry (e.g., chicken or turkey)
- Fish
- Seafood (e.g., mussels or clams)
- Eggs
- Lentils and beans
- Leafy green vegetables (e.g., kale, collard greens)
Vitamin C and Iron
Vitamin C helps your body absorb iron better. That is why it is smart to pair foods high in iron with vitamin C, such as chicken and bell pepper or tomatoes.
Food sources:
- Citrus (orange, lemon, and grapefruit)
- Lemons and limes
- Stawberries
- Kiwi
- Pineapple
- Bell peppers
- Cruciferous vegetables (broccoli, cruciferous vegetables, cabbage, cauliflower)
How to Prevent or Fix Deficiencies
Make Every Bite Count
Focus on whole, nutrient-dense foods. Real food gives your body vitamins, minerals, fiber, and protein in the most natural, usable way.
Include fruits, veggies, lean proteins, whole grains, and healthy fats in your meals.
Eat Small Frequent Meals
When your appetite is low, itโs important to eat small meals regularly throughout the day. In terms of nutrition, make each bite count.
Take a Multivitamin
A multivitamin can help fill in the gaps, but itโs still important to focus on food first. Talk to your healthcare provider about the best option for you.
Ask About Micronutrient Testing
Vitamin D and iron are often included in annual labs, but I recommend going a step further.
Ask your doctor about a micronutrient panel, and check if your insurance will cover it.
If not, you can order tests yourself. For example, Quest Diagnostics offers micronutrient panels that donโt require a doctorโs order. One option (even if Iโm not a fan of the name!) includes key nutrients like:
- B vitamins (B1, B6, B12)
- Vitamin D and E
- Calcium, folate, ferritin
- Iodine, iron, magnesium, potassium, and zinc
The cost is around $289, and it could be a valuable tool, especially if you’ve been on GLP-1 medication for a while or you’re feeling low on energy.
The Impact of Nutrition Deficiencies
Nutrition deficiencies can have serious consequences for your health, affecting everything from your energy levels to your immune system. Without sufficient vitamins and minerals, you might feel tired, get sick more often, or struggle to concentrate.
Can Lack of Nutrients Worsen Hair Loss?
Yes, a lack of nutrients can indeed worsen hair loss. Your hair relies on a steady supply of vitamins and minerals to grow and stay healthy.
Deficiencies in riboflavin, biotin, folate, and vitamin B12 are associated with weight loss.
Over time, these deficiencies can lead to more severe problems like weakened bones, heart issues, brain changes, anemia, depression, night blindness, insulin resistance, and many more.
My Expert Opinion
While research is still evolving, it’s clear that nutrition deficiencies can happen with GLP-1 medications, especially since they reduce appetite. That’s why I always tell my patients: Make every bite count.
Focus on nutrient-rich meals and snacks. You may feel a big difference in your energy, mood, and overall well-being, and you might even reduce some of the common side effects.
Want personalized support while on GLP-1s? Book a consultation with a dietitian. Click here to work with me.