GLP-1 nutrition comes down to four priorities: enough protein, a short list of vitamins and minerals that tend to run low when you eat less, steady fluids and electrolytes, and fiber. When a GLP-1 medication turns your appetite down, each meal has more work to do.
A 2025 joint advisory from four nutrition and obesity medicine organizations names iron, calcium, magnesium, zinc and vitamins A, D, E, K, B1, B12 and C as examples of nutrients of concern. Food comes first, with lab tests and targeted supplements as the backup.
Here's what each nutrient does, where to find it, and why some women's needs differ.
Why Nutrition Needs Change on GLP-1 Medications
GLP-1 medications help you feel full sooner and hungry less often. The joint advisory notes observed calorie reductions of 16% to 39%. Fewer calories also means fewer vitamins and minerals coming in. Shortfalls become especially likely below about 1,200 calories a day for women and 1,800 for men, and stomach side effects can affect absorption too.
Early research points the same way. In a small 2025 study, 69 adults taking GLP-1 medications kept three-day food records. On average, they fell short of recommended amounts of fiber, calcium, iron, magnesium, potassium and vitamins A, C, D and E, and ate less protein than they needed for their body weight. The study was small, but it lines up with the advisory.
If eating anything at all is the struggle, start with what to eat when you're not hungry on GLP-1 medications. This article covers which nutrients matter most and why.
Protein Comes First
Protein helps you hold on to muscle and bone while you lose weight, and it's often the first thing to slip. The advisory notes that targets of 1.2 to 1.6g per kilogram of body weight a day have been proposed during active weight loss, and that a simple goal of 80 to 120g a day may be easier to follow. Your clinician can help you choose a number.
- Eat your protein first, so you finish it before you feel full.
- Choose compact sources like fish, eggs, Greek yogurt, cottage cheese, tofu, beans, lentils and nut butters.
- Pair it with strength training. The advisory stresses that extra protein alone is unlikely to preserve muscle and recommends strength training at least three times a week, plus at least 150 minutes of moderate aerobic activity, matched to your fitness level.
Our article on protein and GLP-1 medications goes deeper.
The Vitamins and Minerals to Watch
The table shows adult daily targets from the National Institutes of Health (NIH) Office of Dietary Supplements for the nutrients you're most likely to discuss with your clinician, with food-first sources for each.
| Nutrient | Daily target for adults | Food-first sources |
|---|---|---|
| Iron | 18mg for women 19–50; 8mg for women 51+ and for men | Lean meat, seafood, poultry, beans, lentils, iron-fortified cereals |
| Calcium | 1,000mg for most adults; 1,200mg for women 51+ and men 71+ | Milk, yogurt, cheese, canned sardines or salmon with bones, kale, broccoli, fortified soy milk |
| Vitamin D | 15mcg (600 IU) through age 70; 20mcg (800 IU) at 71+ | Salmon, trout, UV-exposed mushrooms, fortified milk, eggs |
| Magnesium | 310–320mg for women; 400–420mg for men | Pumpkin seeds, chia seeds, almonds, cashews, spinach, beans |
| Vitamin B12 | 2.4mcg | Fish, meat, poultry, eggs, dairy, fortified cereals, nutritional yeast |
| Zinc | 8mg for women; 11mg for men | Oysters, beef, crab, poultry, beans, nuts, fortified cereals |
Iron
Iron helps red blood cells carry oxygen. Your body absorbs it more easily from meat, poultry and seafood than from plants, but pairing plant sources with vitamin C foods like citrus, peppers or tomatoes helps. Too much iron can be harmful, so take a supplement only if your clinician recommends it.
Calcium and Vitamin D
Calcium and vitamin D work together to keep bones strong. The advisory notes that rapid, substantial weight loss is linked to bone loss, with older adults and women losing more. Dairy is the easiest calcium source for many people. Few foods contain much vitamin D naturally, so fatty fish and fortified foods do most of the work.
Vitamin B12
B12 helps keep nerve and blood cells healthy. It's found naturally only in animal foods, so plant-based eaters need fortified foods or a supplement. NIH advises adults over 50 to get most of their B12 from fortified foods or supplements, since many absorb less from food. It also notes that metformin and acid-reducing medicines can lower B12 absorption, so if you take metformin with your GLP-1 medication, ask about a B12 check.
Magnesium, Zinc and the Rest
Magnesium helps regulate muscle and nerve function. Its richest sources (seeds, nuts, beans and leafy greens) are easy to skip when you fill up fast. For zinc and the other vitamins on the advisory's list, a mix of fruits, vegetables, whole grains, beans, nuts, seeds and lean proteins covers a lot of ground.
Why Some Women's Needs Are Different
Some nutrient targets change with sex and life stage.
- Iron before menopause. Women 19 to 50 need 18mg of iron a day, more than twice the 8mg men and women over 50 need, largely because of iron lost through periods. NIH lists women with heavy periods among those most likely to run low.
- Calcium after 50. The calcium target rises from 1,000mg to 1,200mg a day for women over 50, to help limit bone loss after menopause. Rapid weight loss makes this worth extra attention.
- Folate if you could become pregnant. NIH advises anyone who could become pregnant to get 400mcg of folic acid daily from supplements, fortified foods or both, on top of folate from food, because it lowers the risk of certain birth defects. If you're planning a pregnancy, talk with your prescriber about your GLP-1 medication well ahead of time.
- Muscle in midlife. The advisory notes that low protein intake may contribute to muscle loss, particularly with older age and around perimenopause and menopause.
Fluids, Electrolytes and Fiber
Fluids and Electrolytes
In the U.S., food supplies an estimated 22% of total water intake, so eating less makes drinking more important. The National Academies set an adequate intake for total water, from drinks and food combined, of about 2.7 liters a day for women and 3.7 liters for men.
Electrolytes come from food, too. Women need about 2,600mg of potassium a day and men about 3,400mg, mostly from foods like dried apricots, lentils, potatoes, beans, bananas, milk and yogurt. Vomiting and diarrhea add to losses, and the advisory warns that the resulting dehydration can lead to acute kidney injury.
- Keep a water bottle in sight and sip between meals.
- Count milk, soups, smoothies and water-rich fruit toward your fluids.
- Watch for dark urine, dizziness or a dry mouth.
- If you have heart or kidney disease, or have been told to limit fluids, sodium or potassium, ask your clinician for your own targets.
Read more in electrolytes for GLP-1 users.
Fiber
Fiber helps keep you regular, and the advisory reports constipation in 17% to 24% of people in GLP-1 medication trials. The general target is 14g per 1,000 calories, or about 25g a day for women and 38g for men through age 50. Chia seeds, lentils, beans, raspberries and oats pack a lot into small portions. Add fiber gradually with plenty of fluids, and go easy on high-fiber and fatty foods in the first few days of treatment, as the advisory suggests. Our guide to fiber on a GLP-1 has targets and easy food swaps.
When to Ask for Lab Tests
The advisory recommends regular check-ins on diet, hydration and nutrient levels during treatment. Testing before you start may make sense if you've had weight-loss surgery, a very low-calorie diet, celiac disease or another inflammatory condition, or a past deficiency.
Ask sooner if you notice possible signs of a shortfall the advisory lists: fatigue beyond what you'd expect, excessive hair shedding, flaky or itchy skin, muscle weakness, slow wound healing or unusual bruising. Our guide to hair loss on GLP-1 medications covers shedding in detail.
Your clinician will choose the tests, but these are worth asking about:
- Complete blood count and ferritin if you have periods, especially heavy ones, or eat little meat.
- Vitamin D if you rarely eat fatty fish or fortified foods.
- Vitamin B12 if you're over 50, eat plant-based, take metformin or acid-reducing medicine, or have had stomach or intestinal surgery.
- Kidney function and electrolytes if you've had ongoing vomiting or diarrhea or have kidney concerns.
Bring a list of everything you take, including supplements, and don't start iron or high-dose vitamins on your own.
Where Supplements Can Help
Food should do most of the work. The advisory notes that supplements can be considered for at-risk nutrients, such as vitamin D, calcium, B12 or a multivitamin-mineral, tailored to each person. If you and your clinician decide one makes sense, two auravi formulas fit here.
- Daily Essentials is a two-capsule daily multivitamin that helps fill nutrient gaps when you're eating less.* It includes vitamins A, C, D and B12, folate, zinc and selenium. It contains no iron, calcium or magnesium, so those still need to come from food or a product your clinician recommends. Its folate is L-5-MTHF rather than folic acid, so if you could become pregnant, ask your clinician which form you need. It also contains biotin, which can interfere with some lab tests, so mention it before blood work.
- Hydrate is a wild berry electrolyte drink mix that supports hydration and electrolyte balance.* Each scoop provides 300mg of sodium, 150mg of potassium, 50mg of magnesium, 50mg of calcium and 500mg of taurine, with 5 calories. It's a top-up, not a replacement for potassium-rich foods.
Check with your prescriber or pharmacist before starting either, especially if you take other medications, have heart or kidney concerns or have been told to limit sodium. If you can't keep fluids down, call your prescriber rather than relying on an electrolyte drink.
Frequently Asked Questions
Do I Need a Multivitamin on a GLP-1 Medication?
Not everyone does, but it can be a reasonable safety net when you're eating much less. The advisory lists a multivitamin-mineral among the supplements clinicians can consider for at-risk nutrients. Ask whether one fits your diet and lab results.
Should I Take an Iron Supplement?
Only if testing shows you need it. Iron needs vary by age and sex, and too much can be harmful. If you have periods, especially heavy ones, ask your clinician about checking your iron stores.
How Often Should My Nutrient Levels Be Checked?
There's no single schedule. The advisory recommends regular reassessment during treatment, adjusted to how quickly you're losing weight, your nutrient status and how you're tolerating the medication. A follow-up visit or dose change is a natural time to ask.
Sources
- Mozaffarian D et al. Nutritional priorities to support GLP-1 therapy for obesity: a joint Advisory from the American College of Lifestyle Medicine, the American Society for Nutrition, the Obesity Medicine Association, and The Obesity Society. Am J Clin Nutr. 2025.
- Johnson B et al. Investigating nutrient intake during use of glucagon-like peptide-1 receptor agonist: a cross-sectional study. Front Nutr. 2025.
- Popkin BM et al. Water, hydration, and health. Nutr Rev. 2010.
- Institute of Medicine. Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. National Academies Press. 2005.
- Institute of Medicine. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. National Academies Press. 2005.
- National Institutes of Health, Office of Dietary Supplements. Iron: Fact Sheet for Consumers. Accessed 2026.
- National Institutes of Health, Office of Dietary Supplements. Calcium: Fact Sheet for Consumers. Accessed 2026.
- National Institutes of Health, Office of Dietary Supplements. Vitamin D: Fact Sheet for Consumers. Accessed 2026.
- National Institutes of Health, Office of Dietary Supplements. Vitamin B12: Fact Sheet for Consumers. Accessed 2026.
- National Institutes of Health, Office of Dietary Supplements. Magnesium: Fact Sheet for Consumers. Accessed 2026.
- National Institutes of Health, Office of Dietary Supplements. Zinc: Fact Sheet for Consumers. Accessed 2026.
- National Institutes of Health, Office of Dietary Supplements. Folate: Fact Sheet for Consumers. Accessed 2026.
- National Institutes of Health, Office of Dietary Supplements. Potassium: Fact Sheet for Consumers. Accessed 2026.
- U.S. Food and Drug Administration. Biotin Interference with Troponin Lab Tests: Assays Subject to Biotin Interference. FDA. Accessed 2026.
This article is for educational purposes only and is not medical advice. Talk with your healthcare provider before changing your diet, exercise or supplement routine, especially while taking a GLP-1 medication. *These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.
