How Much Sodium do we need? A Salty Lesson.

Sodium and health is a really controversial topic lately.

The government tells us we shouldn’t be eating more than 2300mg a day.

The keto people tell us that we should be supplementing our diets with more salt.

Influencers are selling electrolyte supplements with huge amounts of sodium in them.

So, who’s right?

Like anything related to nutrition, there’s a lot of nuance here. In this post, I’m going to answer your questions about sodium, and address the circumstances in which you may need less, or more, of it. 

What is sodium?

Sodium is a mineral that our bodies need to function normally. It’s not the same as ‘salt,’ which consists of a sodium ion and a chloride ion (which is why the chemical name for table salt is ‘sodium chloride’). 

Sodium is naturally present in a lot of foods, even ones that you wouldn’t expect like meats, milk, and vegetables. This is in small amounts though – the most sodium-packed foods are ones that have been ultra-processed or cured using salt.

Sodium has been demonized for decades as the cause of assorted health issues. While it’s true that excessive sodium intake can be harmful to health, we can’t make this a blanket statement that applies to everyone.

How does sodium work in our bodies?

We need sodium to maintain fluid balance, and for conduction of impulses in nerves and muscles. The amount we need for these basic functions is estimated at around 500mg a day. 

This is dependent on your sodium levels to begin with, of course, because there are situations where sodium levels are low and need to be replaced. 

Sodium levels can go low when you lose fluids through diet (more on that in a bit), sweat, poop, pee, or vomit, or if you have increased fluid losses from, say, an ileostomy or diuretics. 

They are also affected if you have a condition that causes fluid retention and dilution of sodium in the body – such as heart failure or kidney disease. In these cases, adding more sodium to your diet can be detrimental to health, so we treat the cause of the dilution to bring sodium levels back to normal that way. 

The kidneys are always working to maintain the sodium balance in our bodies.

Let’s say you ran for three hours in 100F heat, and you lost a lot of fluid. Your blood pressure would decrease, which would then send hormonal signals to the kidneys to filter out potassium, and retain sodium and fluid in the body to bring the blood pressure back up.

All of these functions are regulated by hormones called aldosterone and antidiuretic hormone (ADH), among others.

When we consume excess sodium, our blood sodium rises, and our kidneys hold on to fluid to dilute the sodium in our blood.

Eventually, the kidneys get rid of that excess sodium and fluid in urine. 

Things become problematic when someone eats excessive sodium throughout the day, every day. That’s because the kidneys get strained and overwhelmed, and can’t manage the excess sodium in the blood, leading to more chronic fluid retention, which puts stress on blood vessels, leading to increased pressure – aka ‘blood pressure.’ 

High blood pressure causes damage to blood vessels, leading to kidney damage and a risk of heart attack, stroke, aneurysm, vision loss, stomach cancer, and even memory issues, among other things. 

This all sounds scary, but most of us don’t have to micromanage our sodium intake. 

What are the recommendations around sodium?

The average North American consumes around 3400 mg of sodium a day, which is a lot higher than the recommended 2300 mg. 

Kids and babies need between 1200-1800 mg/day.

The majority of our sodium comes from ultra processed and prepared foods, not from the salt shaker in our kitchens. 

The right sodium level for you can be controversial. Some studies have suggested that low levels of sodium in the diet (under 2300 mg/day) don’t impact heart disease risk for people with high blood pressure. There are a lot of people online who are saying that sodium doesn’t affect our health at all, and I’ll address that in a bit.

All in all, the most practical way to manage sodium is to try to limit your consumption of ultra-processed foods as much as you can.

If your blood pressure is normal, and you’re eating a diet that’s mostly whole and minimally processed foods, you probably don’t have to be concerned with the amount of sodium you’re consuming.

Outside of specific diagnoses, some people are more sensitive to salt than others. This seems to be because of an abnormal response by the kidneys to sodium, but there is no common diagnostic test for salt sensitivity.

As with everything, it’s a balance. Some things you eat are going to be high in sodium, because CHIPS. That’s totally fine for most of us – the body can handle the occasional influx of high sodium food. 

When you’re looking at a nutrition label, you’ll want to look at the percent daily value of sodium that the food contains. If it has more than 15%, that means it’s a high sodium choice.

If you’ve had a heart attack, follow the advice of your doctor and RD in terms of how much dietary sodium they recommend. If the heart has sustained damage, or you have heart failure, they’ll probably recommend a lower sodium diet to help avoid further damage to the heart and vessels.

Is MSG a good replacement for salt? Read what I have to say about MSG here.

Sodium and keto

A lot of people who are on low-carb and keto diets take electrolyte supplements, and there are several reasons why they may actually need more sodium. First, the lack of ultra-processed foods in their diets mean that they may be consuming less sodium than the average person.

Second, insulin has been shown to cause reabsorption of sodium into the system instead of elimination through the urine. If someone’s insulin levels are low (and they can be with a diet that contains very few carbs), they may not be holding on to sodium – and an electrolyte supplement can help with that. Some recommendations for sodium on a keto diet can range from 3000-5000+ mg/day.

The initial fluid loss that people experience from not eating carbs can also be dehydrating and lead to increased sodium needs. 

How much water do we need in a day? Here are the recommendations.

This is why you’re seeing a lot of influencers selling electrolyte replacements (I’m not naming any here) and drinking huge cups of water with Himalayan salt. 

Needless to say, if you’re not on a low-carb or keto diet, you’re probably fine without the electrolyte supplements or salty water. The people saying that everyone needs an electrolyte supplement, are wrong (and they’re probably trying to sell you something).

The DASH Diet

The DASH Diet – Dietary Approaches to Stop Hypertension – has been around for decades. Based on the DASH study from 1997, it reads like something that hasn’t been updated….since 1997.

That was before even I got my nutrition degree. 

The diet has two levels of daily sodium – 2300mg, and 1500mg which, as a dietitian, I will tell you is extremely hard to maintain for most people eating a varied diet.

My issues with DASH are many. 

The diet recommends low-fat and fat-free foods like salad dressings (still salty) and dairy.

It limits nuts and seeds to 4-5 servings a week, and meat/fish servings to 6oz a day. Total.

The grain recommendation is, in my opinion, way too high (for carbs and for salt) at 7-8 servings a day.

Fruit servings are too high (4-5 a day) and vegetable servings are too low (4-5 a day).

The diet still maintains that dietary cholesterol should be limited. This has been debunked many times, notably here. It also promotes a low-fat eating pattern, which, ignoring current research, seems to limit even healthy fats, and doesn’t make the distinction between dairy and meat fats. (here) (here)

I’ve never recommended the DASH Diet to anyone for these reasons.

sodium and exercise

Athletes, people who sweat a lot and/or work out strenuously at length (more than 60-90 mins) in hot weather, may need more sodium to replace what they’ve lost. Not replacing sodium can result in hyponatremia, which is dangerously a low sodium level. If this isn’t your situation, and you’re eating on a regular basis, you’re probably fine with plain water. 

This piece from ACE has some good guidelines and charts around replacing electrolytes during and after exercise.

What is POTS? (Postural Orthostatic Tachycardia Syndrome)

POTS causes dizziness and fast heart rate when you go from sitting or lying down, to standing. Basically, your body can’t stabilize blood pressure, leading to these and other symptoms. 

POTS is a very real thing and it’s also quite common. Although we don’t know what the exact cause of POTS is, it seems to be associated with viral illnesses, pregnancy (POTS is far more common in females than males), head trauma, and surgery. People with autoimmune diseases are also more likely to develop POTS. 

There are three types of POTS: hypovolemic, hyperadrenergic, and neuropathic. For people who have hypovolemic POTS, low blood volume causes symptoms. A diet with adequate fluids and up to 10,000 mg of sodium a day (yes, that’s a lot) can help increase blood volume and alleviate symptoms. In this case, electrolyte supplements can help.

Is alkaline water necessary? Here’s the real story on alkaline water and the alkaline diet.

Foods that are high in sodium

You can probably guessed that foods that taste salty – like chips, pickles, fast food, and frozen meals – are high in sodium. I’ve found that pretty much anything from a restaurant is high in sodium, simply because they add a lot of salt. Salt makes things taste good!

Hidden sources of sodium include cottage and regular cheeses, breads and pastries, soy and other sauces, sauerkraut (even if it’s good for your gut, it’s still salty), and salad dressings. Canned foods can also be high in sodium, so if you’re watching your salt intake, choose low-sodium varieties. 

Sodium myths

Myth: Sodium isn’t bad for us; it’s the additives in packaged food that cause heart disease

I’m not into conspiracy theories, but you’ll find a lot of them surrounding sodium (especially on a certain popular electrolyte company CEO’s social feed…just wow)

A diet that’s high in sodium, whether from packaged foods or not, has shown to be deleterious to our health (here) (here) (here). The sugar and lack of fibre in packaged food are something different, but are also associated with risk for disease. 

None of this matters all that much if you’re eating a diet that’s fairly low in ultra-processed and packaged food. 

I’m not sure why anyone would even want to challenge the thinking that excess sodium is harmful to us – a lower sodium diet is something that goes hand in hand with eating more whole foods. Seems like a weird thing to dispute.

Myth: Himalayan pink salt, kosher salt, and Celtic salt are healthier than table salt

Nope. Salt is salt, no matter how pretty it is, or if someone hand-picked it from the most remote place on the planet.

And Redmond Real Salt? It’s salt. All salt is real, please don’t fall for these ridiculous marketing ploys.

Yes, some salts have trace amounts of minerals in them. However, you’d have to eat a lot of salt to get any appreciable effects from these. Don’t eat salt for the iron.

Bobby Parrish of FlavCity has been known to claim that Himalayan salt doesn’t impact blood pressure like other salts, and he’s wrong (what a surprise). All salt is sodium chloride. The chloride doesn’t have much effect on blood pressure, but the sodium still does. As far as amounts of sodium in pink or kosher salt versus table salt, they’re around the same by weight.

A teaspoon of any rock salt may seem to have less sodium than the same amount of table salt, but that’s because more table salt fits onto a teaspoon. That’s all.

Most of the unrefined salts out there aren’t iodized, which can be an issue for someone who isn’t getting enough iodine in their diet.

In a recent Reel, I called out an influencer for suggesting that table salt is bleached. It’s not. Sodium chloride is WHITE. 

It’s a huge red flag when anyone claims that table salt is less ‘healthy’ than other salts.

Myth: Salt helps you absorb water, so you should drink salt water in the morning to help hydrate you all day long

The ‘salt makes water wetter’ hypothesis. I hear a lot of fitness trainers saying this.

While we do need sodium and other electrolytes to absorb water, most of us consume more than enough through food. We only need around 500mg a day for our bodily functions, so you don’t need to add salt to your morning water. Even if you do, it won’t help hydrate you all day, because your kidneys will flush it out pretty quickly.

Please don’t pile more salt onto a diet that’s probably more than adequate in sodium. And most of us definitely do not need to salt our fruit for ‘hydration’:

Long story short: if you’re eating and you aren’t losing a ton of fluids (we talked about this above), you don’t need salt for hydration. 

The bottom line on sodium is this: most of us eat more than enough of it. If you eat a diet high in whole foods, and you don’t have any existing health issues, you probably don’t need to micromanage your sodium intake.