Which multivitamin is best when taking Mounjaro?

Why tirzepatide's appetite effect makes micronutrient planning essential

The SURMOUNT-1 trial, published in the New England Journal of Medicine, found that participants on tirzepatide 15 mg lost an average of around 20–21% of body weight over 72 weeks. That level of weight reduction doesn't happen without a substantial and sustained drop in calorie intake. The moment daily calories fall significantly, so does the raw quantity of vitamins and minerals arriving from food. Most adults fall short of vitamin D and B12 even on a normal diet; on a reduced-calorie plan alongside tirzepatide, those shortfalls tend to deepen.

Vitamin D is particularly worth flagging. It's difficult to obtain in meaningful amounts from food alone in the UK (our latitude and long winters see to that) and the NHS recommends that everyone in the UK consider a daily supplement of 10 micrograms, year-round. On top of that baseline, people restricting calories further have an added reason to keep levels topped up. Iron, folate, calcium, zinc and the full B-vitamin complex are similarly at risk when food volume drops. If you want to understand exactly what to look for in a multivitamin designed around Mounjaro, our dedicated page covers the key nutrients and why each one matters during treatment.

You can read the NHS patient guidance on tirzepatide for a thorough overview of how the medicine works and what to discuss with your care team, including nutrition.

What to look for when choosing a multivitamin on Mounjaro

Not all multivitamins are created equal, and the market is full of products that look comprehensive on the label but contain doses too small to be meaningful. A few practical markers help cut through the noise.

Look for a formula that includes vitamin D3 (cholecalciferol) rather than D2, as D3 is more effectively used by the body. Vitamin B12 as methylcobalamin or cyanocobalamin at or above 2.4 micrograms, folate (ideally as methylfolate rather than folic acid for better absorption in some people), iron at around 8–14 mg for adults, and zinc at 8–11 mg are reasonable targets. Calcium is harder to cover in a single tablet, so some people find a separate calcium supplement useful, particularly if dairy intake has fallen.

Avoid mega-dose formulations, very high doses of fat-soluble vitamins like A and E can accumulate and cause problems. The aim is to fill gaps left by a reduced diet, not to supplement far beyond what the body needs. Our clinical team has put together detailed guidance on finding the best multivitamin while on Mounjaro, including how to read supplement labels sensibly.

It's also worth thinking about the form of the supplement. Chewable or liquid multivitamins are absorbed at least as well as standard tablets for most nutrients, and some people on tirzepatide find large tablets harder to tolerate if nausea is present, especially early in treatment. Take your multivitamin with food (something even as small as a yoghurt is enough) to reduce any stomach irritation.

Timing, absorption and a practical daily routine

One question the prescribers at nume hear regularly is whether Mounjaro affects how supplements are absorbed. Tirzepatide slows gastric emptying, which can affect the rate at which some oral medicines and supplements move through the digestive system. The clinical consensus is that standard oral supplements remain effective, but timing matters for a different reason: if nausea tends to peak in the day or two after your weekly injection, that's probably not the moment to take a large supplement that might sit uncomfortably. Many people find taking their multivitamin on the days between injections, with their main meal, settles into an easy habit.

For women specifically, iron and folate deserve extra thought. Women of reproductive age generally need more iron than men, and folate is important for anyone who might become pregnant. Our page on multivitamins for women on Mounjaro goes into the detail on these nutrients. Bone health is another consideration: if calorie reduction has meant eating less dairy or fewer calcium-rich foods, a multivitamin that includes vitamin D and at least some calcium is a useful starting point, alongside weight-bearing exercise where possible.

For a broader look at how vitamins and nutrients fit into treatment, see our guide on the vitamins most useful during Mounjaro treatment. And if you're exploring what Mounjaro treatment itself involves, the Mounjaro overview covers the medicine's mechanism, licence and what to expect week by week.

The NHS Healthy Weight guidance recommends that anyone on a calorie-restricted plan ensure their diet remains nutritionally complete. If you're weighing up your options, our guide to the best multivitamin to take with Mounjaro can help you make a confident, informed choice. A daily multivitamin covering the UK reference nutrient intakes is a reasonable, low-risk way to do that. It doesn't replace real food, protein adequacy or hydration, all of which matter alongside tirzepatide, but it fills gaps that are genuinely hard to close through appetite-reduced eating alone. That's it. Simple in principle, worth doing consistently.

If you have questions about nutrition during treatment, or want to understand more about starting Mounjaro through a regulated private pharmacy, our treatment and consultation page is the right next step. A prescriber will review your full picture before anything is prescribed.