Vitamins to Take on Ozempic: What Women and Men Actually Need

The vitamins to take on Ozempic are the ones your shrunken food intake can no longer supply, and the shortlist worth checking is iron, B12, zinc, calcium and vitamin D, not a drawer full of supplements bought on faith. The list is similar for women and men, but the priorities differ, and getting that difference wrong wastes money at best and masks a real problem at worst. Eating half as much food means roughly half the micronutrients unless the food is chosen well, so the real story is the same for everyone: food first, targeted testing second, supplements only where a gap is confirmed. This is how I triage it with clients.

Why deficiency risk rises on a GLP-1 medication

No mystery mechanism required: micronutrients travel in food, and you are eating much less of it. A 1,500-calorie day built on protein, dairy, vegetables and grainy carbs covers most needs surprisingly well. A 1,500-calorie day of random grazing does not. The medication also commonly pushes people away from red meat, one of the denser nutrient packages in the trolley, which is where the iron and zinc stories start.

The shortlist, and who each one matters for most

Iron: the headline risk for women, a warning flag for men. Women who menstruate are the highest-risk group, compounded when meat intake drops. Fatigue and hair shedding are the common flags. For men the advice is different in an important way: iron deficiency in men is uncommon, so a low result is not a cue to self-supplement but a cue for your GP to investigate why, because unexplained low iron in men can signal a problem that needs proper follow-up. For everyone, the correct move is a GP blood test for ferritin, never a supplement bought on symptoms; unneeded iron causes its own problems, constipation among them.

Vitamin B12: both, especially low-meat eaters. B12 is found almost exclusively in animal foods, so intakes fall when meat does, regardless of sex. Worth including when your GP runs bloods, and non-negotiable to check for anyone eating mostly plant-based. Long-term metformin users, common among people with type 2 diabetes and among women with PCOS, have an added reason to test. This is one that can only be tested once per year under bulk billing. 

Zinc: quietly more of a men's issue. Australian recommendations sit at 14 mg a day for men versus 8 mg for women, and zinc travels in exactly the foods that shrink first on a suppressed appetite: red meat, seafood and eggs. Zinc also supports wound healing, taste, immune function and testosterone production. A varied protein-forward diet usually covers it for women; men eating very little meat for months are the group most likely to drift short. Oysters, beef, eggs, dairy and legumes are the food answer before any supplement.

Calcium: targets differ by age and sex. Australian recommendations are 1,300 mg daily for women over 50 and men over 70, and 1,000 mg for other adults, including men from 51 to 70. Small appetites rarely reach these numbers without deliberate dairy: three serves most days of milk, yoghurt or cheese, which conveniently also serve your protein target. Fortified soy or oat milks do the job for dairy-free eaters. Supplement only per your GP's advice.

Vitamin D: everyone, test first. Less about food than sun, and deficiency is common in Australian adults of both sexes despite the climate, particularly office workers and anyone sensibly covered up through summer. A simple blood test settles it; supplementation is cheap and effective when indicated.

Fibre, the honorary vitamin. Not a micronutrient, but the shortfall with the most immediate consequences on this medication for women and men alike. If things have slowed down, the full fix is in constipation on Ozempic.

What about a multivitamin?

A basic multivitamin is a reasonable insurance policy during the months of smallest intake, and I have no objection to one. Choose the standard supermarket or chemist multi appropriate to your sex and age, since formulations differ sensibly: men's versions typically drop the iron, which suits the advice above. What a multi is not: a substitute for protein, a treatment for a confirmed deficiency (doses are usually too low), or a reason to skip the blood test.

The supplements I see wasting the most money on this medication: biotin for hair (fixes nothing unless you are deficient, which is rare), greens powders (expensive fibre boosters, there are cheaper options), testosterone boosters marketed at men on weight loss medications (see your GP if you have real concerns), and metabolism boosters (no). Every dollar there is better spent on actual protein.

The order of operations

1. Build the food base: protein at every meal, dairy serves, vegetables, legumes and grainy carbs. This covers most needs even at low intakes.
2. Ask your GP for bloods if you have been on the medication several months, are fatigued, shedding hair, or eat little meat: ferritin, B12 and vitamin D are the usual suspects, and men should treat any low iron as a reason for investigation rather than a supplement aisle trip.
3. Supplement what testing supports, at the dose your GP or dietitian recommends.
4. Reassess; needs change as intake and dose change.

That food base is exactly what the free Muscle-First Checklist builds, and the wider system is at GLP-1 dietitian Australia.

FAQ

Should everyone on a GLP-1 take a multivitamin? Not automatically, but it is a reasonable low-risk insurance policy while intake is very small. Pick a formulation matched to your sex and age, since men's versions sensibly leave out iron. It does not replace food quality or blood testing.

What deficiency is most common on GLP-1 medications? Among women: iron first, driven by reduced red meat and menstruation, then vitamin D and B12. Among men: vitamin D and B12 lead, with zinc the one to watch when meat intake stays low for months. Fibre shortfall is near-universal without planning. Testing beats guessing for all of them.

Do men need different vitamins than women on Ozempic? The shortlist overlaps heavily; the priorities differ. Women carry the iron risk, men should never supplement iron without GP investigation of a low result, zinc needs are nearly double for men, and calcium targets differ by age and sex. Same strategy for both: food first, test, then supplement.

Can vitamins help with Ozempic fatigue? Only if the fatigue comes from a deficiency, most often iron in women or B12 or vitamin D in either sex. More commonly the cause is simply too little food and protein, in which case the fix is an eating strategy, not supplements. Persistent fatigue is worth a GP visit either way.

Do I need electrolytes on Ozempic? There is no tested research to say a daily electrolyte is needed on GLP-1 medications. What I have seen in clinic is anecdotal evidence that having a daily electrolyte drink can sometimes help the late afternoon fatigue some people experience. This is a case by case basis. It helps some people. Something worth a trial if you are experiencing fatigue and your eating is where it should be. Speak to your GP if you have high blood pressure before starting a daily electrolyte drink. 

Becky May, Accredited Practising Dietitian (APD). This article is nutrition education and does not replace advice from your doctor or prescriber. Supplement decisions are best made with your GP, especially alongside other medications.