can glp-1 medications actually cause scurvy? common nutrient deficiencies to watch for

Recently, headlines have suggested that GLP-1 medications like Ozempic, Wegovy, and Zepbound are causing scurvy. Let’s explore this further - is it really accurate?

What Is Scurvy?

Scurvy is a disease caused by severe deficiency of vitamin C (ascorbic acid) over a prolonged period of time — usually 1–3 months of extremely low intake. It used to be common in sailors on long sea journeys.

Vitamin C is essential for:

• Collagen production (the protein that holds skin, blood vessels, joints, and connective tissue together)

• Wound healing

• Immune function

• Iron absorption

• Antioxidant protection

Without enough vitamin C, the body literally cannot maintain connective tissue integrity. Blood vessels become fragile, gums break down, skin bruises easily, and wounds fail to heal.

CAN GLP-1 MEDICATIONS ACTUALLY CAUSE SCURVY?

The widely cited “scurvy” case was not caused by GLP-1 therapy alone. It referred to a man with prior bariatric surgery who had stopped taking his prescribed vitamins and was avoiding fresh produce due to financial hardship.

Scurvy (severe vitamin C deficiency) is rare in developed countries and almost always linked to extreme dietary restriction, malabsorption, alcoholism, or significant socioeconomic barriers — not simply GLP-1 use on it’s own.

That said, dismissing the conversation entirely would also be a mistake.

There is legitimate concern that GLP-1 receptor agonists may increase the risk of multiple nutrient deficiencies and other serious health concerns — not just vitamin C deficiency.

MY CONCERNING PERSONAL EXPERIENCE WORKING WITH PATIENTS USING GLP-1 MEDICATIONS

This is something I experienced first hand years ago when I worked in a bariatric weight loss clinic. The doctors were prescribing GLP-1 medications like Ozempic and Saxenda, which caused patients to have very low appetites.

My job was to counsel them on making healthy choices to support their weight loss journey.

Patients were asked to track their food intake using MyFitnessPal and share their intake with us during their appointments.

I was shocked when I spoke to these patients - many of them were eating very little food.

Maybe a boiled egg and a few slices of cucumber or a rice cake with peanut butter, or maybe the odd protein bar, and that was it for the day.

They simply had no appetite, and if they ate more than that, they experienced digestive upset including nausea, bloating and feeling uncomfortably full.

This was very concerning to me as a nutritionist - I realized there was no way that these patients were going to be meeting their daily nutrition needs.

Not surprisingly, they also reported common signs of deficiencies including brain fog, mood changes, extreme fatigue and hair loss.

How GLP-1 Medications Work (And Why Nutrients Can Become an Issue)

GLP-1 receptor agonists such as:

• Ozempic

• Wegovy

• Zepbound

mimic the hormone GLP-1 (glucagon-like peptide-1). They:

• Suppress appetite

• Slow gastric emptying (how quickly your stomach empties into your intestines)

• Increase satiety (fullness)

• Reduce overall caloric (food) intake

• Alter insulin and glucagon signaling

While this can be a useful tool on a weight loss journey, especially if other attempts have not been successful, clinical trials show dietary caloric intake reductions ranging from 16–39% lower than baseline intake (Blundell et al., Diabetes Obes Metab, 2017; Wilding et al., NEJM, 2021).

That degree of reduction can be therapeutic for weight loss — but it also significantly reduces micronutrient intake - macros such as protein, fat and carbs as well as micronutrients - vitamins.

Delayed gastric emptying - a slower movement of food out of the stomach and into the intestines - is a core mechanism of action of the drugs that can also contribute to:

• Nausea

• Early fullness

• Food aversions

• Bloating

• Constipation or diarrhea

These gastrointestinal effects can further reduce food diversity and fiber intake, potentially altering the gut microbiome and affecting nutrient absorption (Smits & Van Raalte, Diabetes Care, 2021).

why do glp-1 users develop nutrient deficiencies?

Emerging observational data suggest that over 20% of GLP-1 users may experience at least one nutritional deficiency within one year of treatment, particularly when intake is not monitored (various cohort analyses 2022–2024).

The risk is not because the drug “blocks” vitamin absorption directly — it’s primarily due to:

1. Significant reduction in total food intake

2. Decreased dietary diversity

3. Gastrointestinal side effects limiting tolerance

4. Reduced protein intake

5. Possible microbiome disruption impacting nutrient metabolism

When calories drop 20–40%, micronutrients drop too — unless meals are carefully planned.

glp-1 use and the gut: digestive side effects

When your stomach feels off, the last thing you want is a big salad, a steak or a bowl of bean soup. You reach for something bland and easy on the stomach.

GLP-1–induced nausea and early satiety often lead patients to choose:

• Bland foods

• Low-fiber options

• Processed convenience foods

• Smaller, less diverse meals

Reduced fiber intake can alter microbial diversity, decrease short-chain fatty acid production, and contribute to gut inflammation and constipation. Chronic inflammation may impair nutrient absorption in the small and large intestine over time.

This is rarely discussed — but clinically important.

5 common nutrient deficiencies while using GLP-1 medications

Vitamin C deficiency (scurvy) is rare, but other deficiencies may be more subtle and more common.

1. Vitamin D

Vitamin D deficiency is common due to low intake + limited fat absorption, especially in populations in northern climates with limited year round exposure to the sun.

Low vitamin D causes:

• Symptoms: Fatigue, low mood, bone pain, muscle weakness, reduced immune function

• Long-term risks: Osteopenia, osteoporosis, immune dysfunction

While vitamin D supplements range from 1000 IU to the new daily recommendation of 2500 IU, for some people, this might not be enough.

Get your vitamin D level tested and work with a nutritional expert to personalize your intake accordingly.

2. Vitamin B12

One of the most overlooked nutrient concerns with GLP-1 medications is vitamin B12 deficiency.

Vitamin B12 is essential for:

• Healthy red blood cell production

• Nervous system protection (myelin integrity)

• Brain function and memory

• DNA synthesis

• Energy metabolism

• Homocysteine regulation (cardiovascular health)

Because GLP-1 medications significantly reduce appetite — and often reduce intake of animal proteins like meat, fish, and eggs — B12 intake can drop quickly. On top of that, delayed gastric emptying may affect digestion and absorption over time.

Low B12 doesn’t always show up immediately. It can take months or even years to develop, making it a “silent” deficiency.

Common symptoms include:

• Fatigue

• Brain fog

• Numbness or tingling in hands and feet

• Mood changes or depression

• Pale skin

• Balance issues

If left untreated, prolonged deficiency can cause irreversible nerve damage and impact brain function.

Since B12 is found naturally only in animal foods (beef, liver, shellfish, fish, dairy, eggs), those eating smaller portions — or shifting toward lighter, bland diets due to nausea — may not meet their daily needs.

However, there are many fortified foods including cereal/grain products like bread as well as alternative milks and other foods, but these aren’t always the most nutrient-dense foods either and are often “empty” calories.

For someone with reduced food intake, every morsel of food counts - so making nutrient-dense choices (whole foods rich in protein, fat and healthy carbs and vitamins) at every meal and snack is critical.

For individuals using GLP-1 medications, periodic monitoring of B12 levels and ensuring adequate protein intake is essential. In some cases, supplementation may be necessary to prevent long-term neurological and metabolic complications.

Symptoms and risks of deficiency:

• Symptoms: Brain fog, tingling, memory issues, anemia

• Long-term risks: Neurological damage

3. Iron

Iron is essential for oxygen delivery, energy production, brain function, and thyroid health. It forms hemoglobin, the protein that carries oxygen in the blood — and without enough iron, fatigue is almost inevitable.

Menstruating women are already at higher risk of deficiency due to monthly blood loss.

When GLP-1 medications suppress appetite, reduce red meat intake, and cause nausea or early fullness, iron intake can drop even further. Delayed gastric emptying may also impair absorption.

Common signs of deficiency include:

• Fatigue and weakness

• Brain fog

• Hair thinning

• Feeling cold

• Shortness of breath

• Dizziness

Iron from animal foods (red meat, liver, shellfish) is best absorbed. Plant sources (lentils, beans, spinach) are helpful, but less efficiently absorbed and require vitamin C for optimal uptake.

Oral iron supplements are often poorly tolerated, causing constipation and nausea — and may not be well absorbed if digestion is compromised. In more severe cases, or when oral iron isn’t tolerated, IV iron infusions can be used under medical supervision to restore levels more effectively.

For women using GLP-1 medications, monitoring ferritin and iron status is critical. Fatigue during weight loss isn’t always “normal” — sometimes it’s a sign the body is running low on what it needs most.

• Symptoms: Fatigue, hair loss, brittle nails, shortness of breath

• Long-term risks: Iron-deficiency anemia, organ damage, cognitive decline, and significant, long-lasting health issues.

4. Calcium

Calcium is essential not only for strong bones, but also for muscle contraction, heart rhythm, nerve signaling, and hormone regulation.

Because GLP-1 medications significantly reduce appetite and overall food intake, calcium consumption can unintentionally drop — especially if dairy or fortified foods are limited due to nausea or digestive symptoms, smaller meals, or food aversions.

Over time, low intake can contribute to bone loss, particularly in midlife women who are already at increased risk due to hormonal changes in perimenopause and menopause. In midlife and beyond, the recommended daily intake for calcium is 1,200 mg which can be hard to meet with diet alone, especially if you’re avoiding dairy.

Early deficiency may cause muscle cramps or fatigue, but long-term inadequacy can lead to osteopenia, osteoporosis, and higher fracture risk. Ensuring adequate calcium — along with vitamin D and sufficient protein — is critical when losing weight to protect long-term bone health.

If you can’t get enough from food, you may need to consider a calcium supplement.

Good sources of calcium:

• dairy: cottage cheese, milk, cheese

• fortified plant-based milks (soy, almond, rice)

• leafy greens (collard greens, kale, bok choy)

• canned fish with soft, edible bones (sardines, salmon)

• calcium-set tofu

5. Protein

Protein is essential for preserving lean muscle, stabilizing blood sugar, supporting metabolism, maintaining bone density, producing hormones and enzymes, and promoting satiety.

For midlife women, intake needs are higher than the outdated minimum RDA; most experts recommend at least 1.2–1.6 grams per kilogram of body weight per day (roughly 80–110g daily for many women) to protect muscle during aging and weight loss.

To get this much protein you would need:

• 3 servings of meat or fish

  OR

• 2 servings of meat/fish plus a bowl of greek yogourt

  OR

• a scoop of protein powder, 3 eggs and 1-2 servings of meat or fish

Plus you still need to get your fruits and veggies in there, too.

Eating this quantity of food is typically not achievable for someone on GLP-1 medications.

Because GLP-1 medications significantly suppress appetite and cause early fullness, nausea, and smaller meal sizes, many women unintentionally under-eat protein — increasing the risk of muscle loss, metabolic slowdown, blood sugar instability, and eventual weight regain when the medication is discontinued.

Low protein intake can lead to:

• Loss of lean muscle mass

• Reduced metabolic rate

• Poor blood sugar regulation (risk for prediabetes and diabetes and weight regain after medication discontinuation)

High-quality sources of protein include eggs, Greek yogurt, cottage cheese, poultry, fish, lean red meat, tofu, tempeh, lentils, and protein powders, when needed.

Lighter, easier to digest choices like eggs, fish, greek yogourt or lean meat may be better tolerated than fattier cuts of meat or legumes. Due to the fat and fibre content, fattier cuts of meat and legumes make you feel full more quickly.

The Muscle Loss Problem: “Wasting” vs. Healthy Weight Loss

Our culture equates thinness with health. That is a dangerous oversimplification. It is possible to be thin, but very unhealthy.

If weight loss occurs primarily from:

• Muscle loss

• Inadequate protein intake

• Nutrient depletion

That process resembles wasting — defined clinically as involuntary loss of muscle and body mass due to inadequate intake or illness.

Put simply, it’s a very serious health issue.

Lean muscle mass loss is significant in GLP-1 trials. In the STEP 1 trial published in The New England Journal of Medicine, approximately 25–40% of total weight lost was lean mass (Wilding et al., 2021). This is extremely concerning as muscle is critical for health and longevity, as well as supporting metabolism long term - once you discontinue the medication.

Why this matters:

• Muscle regulates glucose disposal

• Muscle maintains metabolic rate

• Muscle protects bone density

• Muscle preserves long-term weight stability

When the medication is discontinued, appetite often returns — but muscle mass may not recover as easily, especially if the person has not been engaging in regular weight training. This may partially explain why weight regain is common after stopping therapy.

The bottom line: being thin does not automatically mean metabolically healthy.

Tips to prevent loss of muscle mass while using GLP-1 medications:

• ensure adequate protein intake: this may require protein powder supplementation, especially if you aren’t eating meat

• weight training: regular weight training 2-3 times per week helps preserve muscle mass, and build additional muscle mass, keeping you strong and metabolically healthy.

What About Bariatric Surgery for weight loss?

Bariatric surgery carries well-established risks of:

• Iron deficiency

• B12 deficiency

• Calcium deficiency

• Fat-soluble vitamin deficiencies

This is due to anatomical changes and malabsorption (Mechanick et al., Endocrine Practice, 2020). Unlike GLP-1 therapy, surgery physically alters the digestive tract, increasing deficiency risk even further due to the inability to properly absorb nutrients from food, or even vitamins.

The scurvy case referenced in media involved prior bariatric surgery and discontinuation of prescribed supplements — not GLP-1 therapy alone.

support for a healthy weight loss journey on glp-1s

GLP-1 medications are powerful metabolic tools. They are not inherently “bad.” For some individuals, they can be life-changing.

But they are not nutritionally neutral.

The combination of reduced appetite + gastrointestinal side effects + lower food volume can lead to increased risk for:

• Micronutrient deficiencies

• Muscle loss

• Bone density changes

• Microbiome disruption

These risks can be mitigated — but only with proper monitoring and support from health care professionals.

If GLP-1 medications are part of your weight loss journey, here’s how to keep yourself healthy and avoid long term health risks:

• Monitor vitamin D, B12, iron, ferritin, and metabolic markers

• Track protein intake with an app like MyFitnessPal

• Ensure adequate fiber

• Consider targeted supplementation - this may go beyond multi-vitamins, you may need higher doses of high quality brands

• Work with a registered nutrition professional for a personalzied plan, as everyone’s journey and nutritional needs are unique

A skilled nutritionist can:

• Help prevent deficiencies by providing a food plan of easy to digest, but nutritionally dense foods

• Provide a personalized supplement plan

• Support lean muscle preservation

• Help manage nausea and indigestion

• Improve food tolerance

• Optimize long-term metabolic health

should i continue using glp-1s?

Here’s the takeaway - GLP-1 medications do not automatically cause scurvy.

But they can create a nutritional environment where nutrient deficiencies become more likely if intake is not intentionally supported.

Weight loss at the expense of muscle, micronutrients, and metabolic resilience is not health — it’s depletion.

If these medications are used, they should be used carefully, strategically, and with ongoing medical and nutritional supervision.

Because true health isn’t about being thinner, it’s about being stronger.

If you’re looking for support on your weight loss journey, book your complimentary discovery call with me today!