Starting a GLP-1 medication can feel like a whirlwind. Weight loss might be the headline benefit of GLP-1s, but these medications can also change how hungry you feel and how much food you want to eat (1). All of a sudden your favorite foods might seem unappealing. They might even turn your stomach.
Along with changes in appetite and how you eat, GLP-1 medications can affect how your whole body feels. Nausea, digestive issues, fatigue are all possible side effects. You might even spot changes to your skin or nails (3). That’s why keeping an eye on key micronutrients is so important: they can help you feel stronger, more energized, and better equipped to manage these changes (3).
How GLP-1s Affect Your Nutrition
GLP-1s, short for glucagon-like peptide 1 receptor agonists, are medications that can help with weight loss and blood sugar control by mimicking a natural hormone in your body (1). They slow down digestion and help you feel full sooner (1). But eating less can also mean you’re taking in fewer essential vitamins and minerals. That means when you’re on these medications, it’s even more important to maintain a balanced and varied diet (2).
Along with macronutrients (protein, fat, and carbs), micronutrients power everything from your energy levels to your immune system (2,3). If you’re not getting enough, you might start to feel extra tired, foggy, or run down, and in some cases, you could have symptoms like nausea (2,4).
You might also like
Micronutrients to Watch on GLP-1s
Want to know one of the best ways to stay on top of your vitamins and minerals? Mix it up at mealtime. A diet full of colorful fruits, veggies, lean proteins, and legumes can go a long way (2). But when you’re on a GLP-1, eating less might mean accidentally skipping meals or feeling full after just a few bites, especially if nausea kicks in. That’s when nutrient gaps can start to add up (3).
Vitamin and mineral deficiencies don’t always show up right away—but over time, they can take a toll on your energy, immunity, and overall health (3). Tracking what you eat in MyFitnessPal can help you spot any nutrient gaps early on. And if something feels wrong, don’t brush it off, check in with your healthcare provider. Here are some important micronutrients to keep an eye on while you’re taking a GLP-1.
Vitamin D
Vitamin D takes on many roles, such as helping with calcium absorption, supporting your immune system, and regulating the nervous system (5). But despite how important it is, about 53 million adults in the U.S. aren’t getting enough (5).
Sunshine helps your body make vitamin D naturally, but that’s not always reliable (5). Your location, time of year, age, and even skin tone all affect how much vitamin D you can produce from the sun (5). And if you don’t eat much dairy, you might be missing a key dietary source, too (5).
Where to get vitamin D (5):
- Egg yolks
- Fortified foods (like some milks, cereals, and plant-based alternatives)
- Fatty fish, such as salmon and mackerel
- Sunshine (in moderation!)
Signs you may not be getting enough (5):
- Muscle weakness
- Fatigue
- Bone pain
Vitamin B12
Vitamin B12 is like a behind-the-scenes powerhouse, it helps your body make DNA, form red blood cells, and keep your nerves and metabolism running smoothly (6). But if you don’t eat a lot of animal products, you could be falling short without even realizing it.
Vegans, older adults, and people who avoid meat or dairy are especially at risk for B12 deficiency (6). That’s why it’s important to be mindful of how much you’re getting, especially when your appetite is reduced on a GLP-1.
Where to get vitamin B12 (6):
- Dairy products like milk and yogurt
- Eggs
- Poultry and meat
- Fish and shellfish
- Fortified foods (like plant-based milks or breakfast cereals)
Signs you may not be getting enough (6):
- Fatigue
- Anemia
- Mouth sores
- Upset stomach
- Confusion
About the Expert
Melissa Jaeger RD, LD is the Head of Nutrition for MyFitnessPal. Melissa received a Bachelor of Arts in Nutrition (DPD) from the College of Saint Benedict and completed her dietetic internship through Iowa State University. In May 2024 she was recognized as the Registered Young Dietitian of the Year awarded by the Minnesota Academy of Nutrition and Dietetics.
Stephanie Saletta, MS, RDis a dietitian and is MyFitnessPal’s in-house nutrition expert and nutrition scientist. Passionate for promoting healthy lifestyles, Stephanie graduated from San Diego State University with a focus on research and disease prevention.
Iron
Iron helps your body move oxygen where it needs to go. It’s a key part of hemoglobin, the protein in red blood cells that keeps your energy up and your muscles working (7).
There are two types of iron: heme iron, which comes from animal foods and is easier to absorb, and non-heme iron, which is found in plant-based sources. Even if you eat meat, you can still fall short, especially if you’re a woman of childbearing age or follow a mostly vegetarian diet (7).
For the tip: Pair plant-based iron sources with vitamin C (like citrus or tomatoes) to help boost absorption (7).
Where to get iron (7):
- Red meat, poultry, and seafood (heme iron)
- Beans and lentils (non-heme iron)
- Tofu
- Spinach and other leafy greens
- Iron-fortified cereals and grains
Signs you may not be getting enough (7):
- Fatigue
- Weakness
- Pale skin
- Anemia
Electrolytes (sodium, potassium, magnesium)
Electrolytes might sound like something from a sports drink commercial, but they’re actually essential for keeping your body balanced. These minerals help support nerve and muscle function, and keep your fluid levels in check (8).
Nausea, vomiting, or diarrhea are common GLP-1 side effects, and can lead to electrolyte loss quickly (1,2,3). That’s why it’s smart to be mindful of your intake, especially if those symptoms linger (8).
Where to get key electrolytes (8):
- Sodium: Table salt, broth, deli meat (9)
- Potassium: Bananas, white beans, potatoes (10)
- Magnesium: Leafy greens, nuts, whole grains, bananas (11)
Signs you may not be getting enough (8):
- Muscle cramps
- Fatigue
- Nausea
- Vomiting
- Confusion
If you’re noticing signs like muscle cramps, fatigue, or dizziness, it’s worth checking in with your healthcare provider to make sure your levels are where they should be.
How to Stay on Top of Your Micronutrient Intake
When you’re eating less on a GLP-1, you need every small serving to pack a big nutritional punch. Think smaller meals and snacks that still deliver a solid hit of vitamins and minerals.
Not sure what that looks like? Try:
- A protein smoothie with spinach and frozen berries
- A hard-boiled egg and a handful of almonds between meals
- Greek yogurt topped with chia seeds and sliced banana
- A beef stick and string cheese on your way out the door
- An extra egg in your morning scramble or a side of sautéed leafy greens
Frequently Asked Questions: Micronutrients and GLP-1s
Can GLP-1s cause vitamin deficiencies?
Current research does not show that GLP-1s directly cause vitamin deficiencies (2). Depending on individual diet, lifestyle, and other medications, some people are at an increased risk for developing or worsening vitamin deficiencies while taking a GLP-1 (3).
What micronutrients should you be aware of when taking GLP-1 medication?
Some key micronutrients to be aware of include vitamin D, vitamin B12, iron, sodium, potassium, and magnesium. (2, 3)
Do I need to take supplements on GLP-1s?
“Not everyone will need a supplement, but it’s important to have this conversation with your health care team such as your registered dietitian and physician,” says Melissa Jaeger, RD, LD, MyFitnessPal Head of Nutrition. “They can review your diet, symptoms, any lab work and your health history to determine if a supplement may be right for you.”
What are the signs of nutrient deficiency while on a GLP-1?
While signs may vary from person to person you may notice weakness, fatigue, brittle nails, pale skin, nausea, bone pain, brain fog, digestive issues and more (2).
Are some people more at risk than others?
“Yes—especially if you had nutrient gaps before starting a GLP-1 or take other medications that affect absorption. Having GI side effects like vomiting or diarrhea also increases risk for nutrient gaps because you absorb fewer nutrients,” says Stephanie Saletta, RD, Lead Nutrition Scientist for MyFitnessPal. “That’s why a personalized approach is so important.”
How can MyFitnessPal help me track my micronutrient intake?
“Logging your meals and snacks in MyFitnessPal makes it easy to see which nutrients you’re getting—and which ones you may need more of,” says Melissa Jaeger, RD, LD, MyFitnessPal Head of Nutrition. “You can track micronutrients like iron, sodium, potassium and more and then use those insights to make food choices that help you hit your daily nutrient goals.”
The Bottom Line
GLP-1s can be a powerful tool for weight loss and better health—but they often work best when paired with a nutrient-dense diet (2,3). Prioritizing high-quality foods can help you stay energized, avoid nutrient deficiencies, and feel your best throughout your journey (2,3). Your food choices matter and MyFitnessPal is here to support you along the way!
The post Micronutrients and GLP-1s: What You Should Know appeared first on MyFitnessPal Blog.
