Most horse owners have asked the question at some point, and we've had our fair share here at EquiNatural as well. So what's the truthful answer?

In an ideal world?  Well, I think the only honest answer I can give here is… they shouldn’t!

But in the real world we’re living in - and whether human or horse, mineral support is no longer a luxury. It’s a necessity. And winter is the perfect time to understand why.

The modern world problem – for us and our horses

Let’s start with a factor we often forget: Our horses don’t live in a natural environment anymore – and neither do we.

For us humans, the research is clear - our soil, food, and environment have changed dramatically in the last century. And the same forces that are depleting human health are quietly affecting our horses, too.

Here’s the bigger picture.
1. Our soils have changed

There’s an often-quoted (but accurate) example: a carrot today contains around 75% less magnesium than a carrot 100 years ago.

Why? Since the 1950s-60s, intensive modern farming practices have steadily stripped minerals out of our planet’s soils – and that includes our UK soil.

And here’s the unavoidable knock-on effect - anything that grows in depleted soil is going to be far less nutrient-rich than it once was.

Our UK grasslands grow from this same soil, and lest we forget, hay is dried grass. So our grass forage – whether fresh or dried – is simply not as nutrient-dense as it used to be. It really is that simple.

2. Modern equine feeds aren’t the answer

Many bagged feeds are:

• made from processed, refined ingredients
• bulked with cheap fillers like wheat, corn, and soya
• often genetically modified
• flavoured with molasses or artificial sweeteners so it tastes nice, so keeps us buying it
• mixed with synthetic vitamin/mineral premixes

None of this resembles what a horse evolved to eat.

These feeds can skew the gut microbiome, contribute to inflammation, and leave horses nutritionally "full but empty" – exactly the same way humans become overfed and undernourished on modern processed diets.

3. Environmental toxins add another layer

Fertilisers, herbicides, pesticides, fungicides, vehicle emissions, industrial chemicals… like us, horses live in this same toxic world. And both humans and horses burn through more minerals when detoxifying environmental chemicals, which raises daily nutritional needs even further.

Put all this together and we reach the unavoidable conclusion - your horse cannot reliably get everything they need from forage alone.

Why nutrients matter so much more than we realise

We all know nutrients are good for us, but they’re much more than that - they're the co-factors powering millions of chemical reactions every single day.

Every enzyme – every little biochemical machine in your horse’s body – needs a nutrient partner to work properly:

• Cellular energy
• Muscle metabolism
• Nerve signalling
• Detox pathways
• Hoof and coat tissue
• Immune resilience
• Stress response
• Red blood cell formation

None of these processes function comfortably or efficiently without the right nutrients in place. And our horse doesn’t need huge amounts – we're talking micro-doses most of the time, but they need the right amounts, in the right forms, in the right ratios to each other, and from the right sources - not fake, made-in-a-lab synthetic.

‘Frank’ deficiency vs ‘subclinical’ deficiency

In the scientific world, the focus is shifting too:

“First things first – addressing frank nutrient deficiencies must remain a priority in the age of precision nutrition." (https://ajcn.nutrition.org/article/S0002-9165(23)46263-6/fulltext)

A quick bit of science for you. A frank deficiency is a nutritional or medical deficiency with obvious, overt clinical symptoms, whereas a subclinical deficiency has negative health effects but no clear or apparent symptoms. 

In humans, a frank deficiency causes obvious illness – think scurvy (vitamin C deficiency) or rickets (vitamin D deficiency).

Our horses can also have frank deficiencies – but these are less common. What we see far more often in the UK is subclinical deficiency, where:

• the horse isn’t getting enough of a mineral to function optimally
• but it’s not low enough to cause an obvious disease
• so the problem smoulders under the surface

Subclinical mineral deficiencies can show up as:

• poor hoof quality
• winter coat dullness
• low-grade muscle tension
• behavioural changes
• metabolic struggles
• sensitivity to seasonal changes
• slow recovery after exercise
• reduced stress tolerance

On the outside, the horse looks fine, but inside? Things are working harder than they should.

Optimal vs adequate – the real difference

This is where functional medicine gives us a brilliant lens.

Even in humans, the difference between enough to avoid disease and enough to function at your best can be ten- to a hundred-fold.

This same principle applies to our horses - the minimum needed to avoid a clinical deficiency? Small. But the level needed for optimal metabolic, structural, and immune resilience? Much higher.

And with depleted soil, processed feeds, environmental toxins, and stress – our horses’ bodies are using more minerals than ever. This is why a balancer matters.

Why UK forage can’t do the job alone

Even the best UK hay or grass is consistently low in (average per day elemental values:

• Lysine (10g/day, 20g for optimal needs)
• Magnesium (12g )
• Copper (400mg)
• Zinc (1.2g)
• Phosphorus (1.25g)
• Selenium (1mg)
• Sodium (20g/day, double if in hard work/sweating)

And in winter, with hay-based diets, horses also need:

• Omega-3 fatty acids (missing from dried forage)
• Vitamin D (if rugged or stabled)
• Prebiotic fibre to support hindgut fermentation

So, yes… even if the forage looks lovely, it simply can’t meet these essential daily needs. These aren’t extras - they’re the gap-fillers nature once provided – but no longer can.

Where minerals meet hydration - the winter twist

Here’s the part most horse owners don’t realise - mineral balance and hydration are inseparable.

You cannot support optimal mineral use unless the horse is hydrated. And a horse cannot stay properly hydrated unless they are getting the minerals that regulate fluid balance.

This matters most in winter, when dehydration is the #1 cause of impaction colic. And this is where functional medicine – human or equine – becomes beautifully clear.

Here’s the winter domino-effect in action:

• Cold blunts thirst.
• Horses urinate more in winter.
• They lose sodium without noticing.
• Sodium regulates thirst.
• Less sodium = lower thirst = lower water intake.
• More hay intake increases water demand.

Minerals + hydration are two halves of the same equation, so let’s look at what hydration really means in winter.

Winter hydration - the hidden colic trigger

Inspired by insights from Dr Juliet Getty, PhD

Winter is the season where horses quietly drift toward dehydration long before any obvious signs appear.

• Cold reduces the thirst mechanism
• Less ADH (the hormone that tells the kidneys to conserve water) = more urination = more water loss.
• Vasoconstriction gives the body a false sense of being hydrated
• Sodium concentration rises, then falls – suppressing thirst further
• Hay intake increases, raising water requirements

All of this quietly increases the risk of winter colic.

Salt - the foundation of winter hydration

Salt supports natural thirst and maintains the sodium balance that keeps the hydration system working properly, so before anything else, a horse needs apx 20g of plain salt per day – year-round, in the feedbowl every day so we know our horses is getting it.

NB: don’t add salt directly to your horse’s water bucket – doing so may cause them to refuse the bucket entirely, putting them at increased risk of dehydration. Offer salt water separately by all means, but never as the only choice - no salty surprises 😉.

Electrolytes aren’t just for summer

Most people think electrolytes belong in July… not December. But here’s the little winter secret no one talks about - your horse may actually need them more in cold weather than in heat.

Why? Because electrolytes aren’t about sweat dripping down their sides – they’re about everything that keeps your horse feeling well and functioning smoothly.

Electrolytes are simply electrically charged minerals – sodium, potassium, magnesium, calcium – and they’re involved in pretty much every behind-the-scenes job:

• keeping cells comfortably hydrated
• helping muscles work without tightening or fatiguing
• keeping nerves firing calmly and correctly
• maintaining steady fluid balance
• supporting healthy circulation
• helping the body use energy efficiently

And here’s the winter twist. Even when your horse looks dry and unsweaty, they’re still quietly losing electrolytes through:

• winter schooling sessions
• sweating under rugs (sneaky but common!)
• increased urination when it’s cold
• general metabolic stress

All of which means their mineral reserves drain faster than we realise.

And remember - add electrolytes as well as daily salt – not as a replacer.

They’re especially handy for:

• ridden horses in winter
• unclipped-but-rugged horses who will warm up quickly under there
• metabolic horses who struggle with mineral balance
• stabled horses (more pee = more mineral loss!)
• anyone travelling, hacking, or competing through winter

The easiest way? Just top-dress electrolytes onto a meal.

How to encourage winter drinking

• If you’ve got a kettle on the yard, add some hot water to make a warm bucket.
• Add winter water buffet flavours
• Apple bobbing anyone?!
• Add moisture to feeds - soaked cobs/pellets

Consistent, accessible water is one of the most effective winter colic prevention strategies.

Bottom line - minerals + hydration = winter resilience

A mineral balancer isn’t simply you being nice to your horse - it’s foundational nutrition in a world where:

• soils are depleted
• feeds are processed
• environmental toxins are high
• winter increases metabolic strain
• hay-based diets miss key nutrients
• dehydration risk is highest

Think of it like this:

Minerals are the spark plugs.
Hydration is the fuel.
Your horse needs both to run smoothly – especially in winter.

Your horse simply wasn’t designed for:

• depleted soil
• processed feeds
• modern environmental chemicals
• stabling, rugs, and artificial routines
• hay-based winter diets
• cold-weather dehydration

But they are designed to thrive when given the right building blocks. And minerals – supported by steady winter hydration – are one of the most powerful, foundational tools we have to help them stay healthy, resilient, and comfortable all winter long.