The best Prime Day supplement deals to shop in October

There are discounts on probiotics, vitamins, protein powders and more thanks to Amazon Prime's Big Deal Days

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If you can't get sufficient vitamins and minerals through your diet alone, then supplements are a great option. Plenty of people use these tablets, powders and gels to make sure they're hitting their recommended daily dosage.

It can be pricey to stock up on these supplements, but luckily Amazon's October sales event (which is officially called Big Deal Days) has arrived and brought plenty of discounts with it. I've trawled through the sales to find the best savings and rounded them up below.

You need to be a Prime member to access some of these deals, but the good news is you can get a 30-day free trial on the platform, and cancel when the sales have ended.

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My US Amazon picks

These are the best Prime Day supplement deals you can buy in October.

  • Mason Natural daily multivitamin: 20% off this vegan-friendly multivitamin ($6.36)
  • Magnesium: Over 50% off from Nature's Bounty ($7.10)
  • Probiotic: Amazon Basics probiotics are now as cheap as $10.27
  • B12: These Nature Made Vitamin B12 softgels are just $9.48 (a 60% reduction)
  • Melatonin: Save 56% on these sleep-promoting Natrol Melatonin 5mg ($9.59)
  • Vitamin D: Grab these sugar-free Vitamin D3 gummies for $8.69 (54% cheaper)
  • Protein powder: Popular Optimum Nutrition flavors are 40% cheaper on Amazon
  • Whey isolate: 36% off Sports Research chocolate flavored protein powder

Prime Day US supplement deals

Mason Natural multi-vitamin with iron: was $7.99, now $6.36

Mason Natural multi-vitamin with iron: was $7.99, now $6.36

Save 20% These mini tablets are easier to swallow, thanks to their smaller size, and suitable for vegans. They contain vitamins A, C, D, E, B12 and more, along with calcium and iron.

Amazon Basics Probiotic 5 billion CFU: was $12.11, now $10.77 on Amazon

Amazon Basics Probiotic 5 billion CFU: was $12.11, now $10.77 on Amazon

Save 15% These Amazon Basics pills were already a good price, but now they're even more pocket friendly. As a reminder, probiotics add to the overall amount of “friendly” bacteria in your gut. Taking them could help relieve gas, bloating and constipation, if these issues have been caused by an upset gut microbiome.

Nature's Bounty Magnesium 500mg 200 count: was $15.05, now $7.10 on Amazon

Nature's Bounty Magnesium 500mg 200 count: was $15.05, now $7.10 on Amazon

Save 53% Magnesium is important for your muscle, nerve and bone health. Despite this, not everyone is getting enough, which is where supplementation can help. This vegetarian option from Nature’s Bounty is now very well-priced, at less than $0.09 per tablet.

Nature Made Vitamin B12 1000 mcg: was $23.89, now $9.48 at Amazon

Nature Made Vitamin B12 1000 mcg: was $23.89, now $9.48 at Amazon

Save 60%. B12 is one of the most common vitamin deficiencies. As it’s mostly found in animal food sources, it can be hard for vegans to get their fill of it. These plant-based softgels make it a bit easier to hit the recommended daily intake, and they have a 4.7 star average user rating too.

NatureWise 5mg melatonin gummies: was $21.99, now $9.59 at Amazon

NatureWise 5mg melatonin gummies: was $21.99, now $9.59 at Amazon

Save 56% Melatonin is a popular sleep aid, which is supposed to help your body when it’s low on this sleep-inducing hormone. Research indicates that melatonin supplements help you fall asleep faster and achieve more restful sleep. These vegan tablets have a strawberry flavor, and dissolve quickly.

Nature Made sugar-free D3 50 mcg gummies: was $18.99, now $9.15 at Amazon

Nature Made sugar-free D3 50 mcg gummies: was $18.99, now $9.15 at Amazon

Save 52% It can be hard to sufficient amounts of vitamin D all year round, as it’s mostly provided by sun exposure. We’re in the sunny months now, but if you want to make sure you’re stocked up for winter, take advantage of this better-than-half-price deal.

Jarrow Formulas digest sure probiotic tablets: was $32.49, now $15.10 at Amazon

Jarrow Formulas digest sure probiotic tablets: was $32.49, now $15.10 at Amazon

Save 54% Probiotics add to the overall amount of “friendly” bacteria in your gut. Taking them could help relieve gas, bloating and constipation, if these issues have been caused by an upset gut microbiome. There’s a hefty $20 saving on this 30-pack of probiotic tablets, which can be taken every day.

Nature's Way Alive! women's daily gummy multivitamins: was $22.99, now $17.27 at Amazon

Nature's Way Alive! women's daily gummy multivitamins: was $22.99, now $17.27 at Amazon

Save 25% These daily multivitamin tablets contain 16 different vitamins and minerals, including vitamins A, C, D and B12. They also have added calcium and are completely vegetarian. Buyers rave about the value of this tub, which has 150 gummies inside.

Nature's Way Alive! men's daily ultra multivitamins: was $29.99, now $18.80 at Amazon

Nature's Way Alive! men's daily ultra multivitamins: was $29.99, now $18.80 at Amazon

Save 37% These tablets contain all the usual things you would want from a multivitamin, like vitamin A, C, D and B12. It also comes with added zinc, which is a nutrient partly responsible for a healthy immune function in the body. This 60-pack of tablets has been reduced by a hearty 50%, making it easier to stock up.

Prime Day protein powder deals

Pre-mixed Premier chocolate protein shake: was $29.99, now $22.39 on Amazon

Pre-mixed Premier chocolate protein shake: was $29.99, now $22.39 on Amazon

Save 30% No-one likes a lumpy protein shake, which is why it's nice to have this smooth, pre-mixed option on hand from Premier. It's got an impressive 30g of protein in each portion, too, and has a 4.5 star rating on Amazon.

GNC Pro Performance unflavored protein powder 1.85lb: was $39.99, now $31.99 at AmazonSave 20%

GNC Pro Performance unflavored protein powder 1.85lb: was $39.99, now $31.99 at Amazon

Save 20% If you hate the synthetic sweetness of flavored protein powders, this could be a good option. The unflavored whey product packs 24g of protein per serving, which could help you hit your muscle-building goals. Stir it into your breakfast, mix it into a smoothie, or bake it into a sweet treat.

Sports Research whey protein isolate powder 5lb: was $75.95, now $48.27 at Amazon

Sports Research whey protein isolate powder 5lb: was $75.95, now $48.27 at Amazon

Save 36% This is a good price for a 5lb bag of protein powder. For comparison, Optimum Nutrition's 5lb tub usually costs over $80. It has an impressive 4.4 star rating and people praise the rich, creamy flavor of the product.

Optimum Nutrition gold standard whey protein powder 2lb:was $41.99, now $25.499 for Prime Members

Optimum Nutrition gold standard whey protein powder 2lb: was $41.99, now $25.499 for Prime Members

Save 39% If you’re a fan of protein powder, then you’re probably already familiar with Optimum Nutrition. The brand’s expansive list of flavors and reasonable prices have made it a huge hit with consumers. It's rare for this brand to be discounted, so grab this deal while stocks last.

Orgain Organic Vegan Protein Powder 2.03 oz: was $30.39, now $19.99 at Amazon

Orgain Organic Vegan Protein Powder 2.03 oz: was $30.39, now $19.99 at Amazon

Save 29% This vegan product is made from pea protein, rice protein and chia seeds and is soy-free. You can save an extra 5% if you subscribe to a regular purchase. It's a customer favorite, with a 4.5/5 star average and over 65,000 ratings.

Dymatize ISO100 gourmet chocolate 5lb tub: was $94.67, now $66.47 on Amazon

Dymatize ISO100 gourmet chocolate 5lb tub: was $94.67, now $66.47 on Amazon

Save 30% This is a good price for protein powder, working out at slightly less than $1 per serving. Dymatize mixes nicely and doesn’t taste overly sweet. This particular chocolate flavor packs in 25g of protein and 120 calories.

Premier vanilla milkshake protein powder: was $23.99, now $17.51 on Amazon

Premier vanilla milkshake protein powder: was $23.99, now $17.51 on Amazon

Save 27% This is a high-protein powder, offering 30g of protein in a scoop. Per serving, it’s more expensive than others in this round-up, coming in at $1.03 for each portion. But it’s smaller size might suit someone who wanted to try a protein powder for the first time.

FAQs

When is the next Prime Day and is it only once a year?

Amazon's summer Prime Day event started on Tuesday, July 16th, and drew to a close at midnight the following day. But Amazon's second sales event (called Big Deals Day) is happening right now and will run from October 8th to October 9th.

While it's unlikely that Amazon will hold another special sales event this year, they will undoubtedly be taking part in Black Friday on November 29th.

Is it worth buying supplements during Prime Day?

While you should aim to get most, if not all, nutrients from your diet, it's not always possible to get everything your body needs from food alone and supplements can help address vitamin deficiencies.

If you eat a primarily plant-based or vegan diet, you may want to supplement your diet with vitamin B12, typically found in meat and other animal products. If you don't get enough exposure to sunlight, you might want to top up your vitamin D intake.

Our needs change over the years, so it's worth using supplements as you age too, but always seek advice from your doctor before taking a new supplement.

Ruth Gaukrodger
Fitness Editor

Ruth Gaukrodger is the fitness editor for Fit&Well and its sister site Coach, responsible for editing articles on everything from fitness trackers to walking shoes. A lot of her time is spent setting up testing protocols for our in-depth buying guides and making sure everything is reviewed to a set standard, so you can be confident we only recommend the best products on the market.

When she's not wrestling with equipment in our dedicated testing centre, you can find her pursuing running PBs around the streets of London or improving her yoga skills from the comfort of her living room. She’s a keen believer in working out for enjoyment first and is always open to hearing about new, fun ways to exercise.