Sodium For Babies

As a parent, you’ve likely heard that salt shouldn’t be added to your baby’s food. The common reasons are:

• Potential damage to developing kidneys
• Predisposing them to blood pressure issues later in life
• Forming a preference for salty foods

But what’s the truth behind these claims? How much sodium is too much? And what does the research actually say?

Before diving in, it’s important to note that we are not recommending a high sodium diet for babies. But let’s zoom out and look at the bigger picture: reassessing what we know, acknowledging gaps in research, and finding practical ways to reduce fear while making family feeding easier and more enjoyable.

Sodium vs. Salt—What’s the Difference?

While often used interchangeably, salt and sodium are not the same. Salt (commonly added to food) is made up of sodium and chlorine. Sodium itself is an essential mineral found in foods such as milk (including breastmilk and formula), eggs, meat, and vegetables.

As a guide:

• 1 teaspoon of salt = 2,300 mg of sodium

Current Sodium Guidelines

There isn’t enough data to set an exact RDI (recommended dietary intake) for infant sodium intake. Instead, guidelines use an AI (adequate intake), which is an estimate based on what’s believed to be adequate for healthy infants. In Australia, the AIs for infants are:¹

• 0-6 months: 120 mg/day
• 7-12 months: 170 mg/day

Interestingly, in the US, the AI for 7-12 months is set at 370 mg/day—more than double the Australian recommendation!²

Sodium and Kidney Function

Excess sodium has long been thought to put strain on developing kidneys. However, our bodies have backup systems that help maintain the right sodium balance. Therefore, the risk of sodium toxicity (hypernatraemia) is rare. If it does occur, it is usually as a result of dehydration, gastroenteritis or infection, rather than excess sodium intake from food.^3,4

Sodium and Blood Pressure

Concerns about sodium intake leading to high blood pressure later in life are commonly raised. However, the evidence isn’t conclusive. Some studies show a link, while others suggest different factors—such as early solids introduction—may be involved.

One study, which compared the impact of sodium ingestion at 4 months, 8 months and 7 years on blood pressure, found that while there did seem to be an increase in blood pressure at 7 years old in the group that ingested more sodium at 4 months, the same was not true when looking at sodium ingestion at 8 months and 7 years. It is also interesting that the higher sodium group at 4 months old were still consuming LESS than the recommended amount of sodium for this age group, suggesting that something else may have been contributing to the elevation in blood pressure.⁵

Sodium and the Preference for Salty Food

Research does not support the idea that offering salty foods in infancy leads to a lifelong preference.⁶ Children do have a natural liking for salty flavours, but this doesn’t result in consistently higher sodium consumption later in life.

So, What Does This Mean For Your Family?

While we don’t recommend a high-sodium diet, there is no need for extreme caution when preparing meals at home. If you’re cooking from scratch with whole foods, adding a moderate amount of salt is fine for the whole family, including your baby. This will make mealtimes easier.

If you rely more on processed or fast foods, it’s important to be aware of the high sodium content in these products, as they can contribute the bulk of your child’s sodium intake. Keep meals balanced, fresh, and minimally processed, focusing on whole foods like fruits, vegetables, and quality proteins. Research suggests that children are consuming the majority of their sodium intake from processed and ultra processed foods, not from home cooked foods that have been seasoned with moderate amounts of salt.^7,8

Need More Guidance?

If you have any specific concerns about your baby’s sodium intake or other nutritional needs, our team of nutritionists, dietitians and naturopaths can answer your questions and help you create a balanced, personalised plan for your family. Visit our Online Clinic for support.

References

• 1. National Health and Medical Research Council. Eat For Health. Nutrient Reference Values for Australia and New Zealand, Sodium, 2017 https://www.eatforhealth.gov.au/nutrient-reference-values/nutrients/sodium(accessed 29/10/24)
• 2. National Academies of Sciences, Engineering, and Medicine. Dietary Reference Intakes for sodium and potassium. National Academies Press, 2019.
• 3. Forman S, Crofton P, Huang H, Marshall T, Fares K, McIntosh N. The epidemiology of hypernatraemia in hospitalised children in Lothian: a 10-year study showing differences between dehydration, osmoregulatory dysfunction and salt poisoning. Arch Dis Child. 2012 Jun;97(6):502-7. doi: 10.1136/archdischild-2011-300305. Epub 2012 Apr 3. PMID: 22493405.
• 4. Kaiser P, Borte M, Zimmer KP, Huppertz HI. Complications in hospitalized children with acute gastroenteritis caused by rotavirus: a retrospective analysis. Eur J Pediatr. 2012 Feb;171(2):337-45. doi: 10.1007/s00431-011-1536-0. Epub 2011 Aug 11. PMID: 21833497.
• 5. Brion, MJ., Ness, A., Davey Smith, G. et al. Sodium intake in infancy and blood pressure at 7 years: findings from the Avon Longitudinal Study of Parents and Children. Eur J Clin Nutr 62, 1162–1169 (2008). https://doi.org/10.1038/sj.ejcn.1602837
• 6. Liem DG. Infants’ and Children’s Salt Taste Perception and Liking: A Review. Nutrients. 2017 Sep 13;9(9):1011. doi: 10.3390/nu9091011. PMID: 28902163; PMCID: PMC5622771.
• 7. Quader ZS, Gillespie C, Sliwa SA, Ahuja JK, Burdg JP, Moshfegh A, Pehrsson PR, Gunn JP, Mugavero K, Cogswell ME. Sodium Intake among US School-Aged Children: National Health and Nutrition Examination Survey, 2011-2012. J Acad Nutr Diet. 2017 Jan;117(1):39-47.e5. doi: 10.1016/j.jand.2016.09.010. Epub 2016 Nov 3. PMID: 27818138; PMCID: PMC5458522.
• 8. O’Halloran SA, Grimes CA, Lacy KE, Nowson CA, Campbell KJ. Dietary sources and sodium intake in a sample of Australian preschool children. BMJ Open. 2016 Feb 4;6(2):e008698. doi: 10.1136/bmjopen-2015-008698. PMID: 26846894; PMCID: PMC4746469.