The 411 on Immunity (Without the Gimmicks)

Contributing Author: Isabelle Wilson

citrus fruits

We’re officially in the thick of winter, and everyone’s sick. Plans are being cancelled left and right due to a case of the sniffles or a nasty case of Covid19.

Since March of 2020, it seems like “immunity” is all that’s on our minds! It’s a popular buzzword in the media, but what does immunity really mean? I think now more than ever my clients are taking elderberry and other supplements to boost their immune system. I’ve even seen claims on sugar-laden cereal boxes that their product is “good for immunity” – everyone is jumping on this bandwagon. According to Meriam-Webster, immunity is “a condition of being able to resist a particular disease especially through preventing development of a pathogenic microorganism or by counteracting the effects of its products.” The aim of this post is to discuss how to form habits that will improve a child’s immunity right from the start (day 1 of life!). There are lots of non-nutrition related ways to build up the immune system, too, but since I’m an RD I’ll stick to the food aspects. If you’re a parent of an infant or toddler, you’ll definitely want to keep reading!  

Age 0-6 months: Babies are born with some natural immunity that they acquire from their mother during gestation. One of the best ways to promote continued stellar immunity is to breastfeed your baby, especially for the first few days of life when the mother is making colostrum. This is the “first milk” that is high in vitamins, minerals, and antibodies to boost their immune system. Even if you can’t or choose not to breastfeed, the colostrum can be hand-expressed and given to baby who will reap the benefits. Continued breastfeeding, if feasible and desired, will continue to expose baby to more antibodies further bolstering their immune system. 

Age 6+ months: Generally babies are able to start eating solid foods around 6 months of age. This is where some major microbiome building can happen! If you’ve never heard of the microbiome, it’s the community of bugs that live in the gut that can either strengthen or dampen lots of areas of your health. One of the goals in feeding your baby should be to build up as diverse of a microbiome as you can. The more bugs, the better health and immunity. The way we do this is by eating lots of different fiber rich foods! Fiber can be found in any plant food; think fruits, vegetables, nuts, seeds, beans, and whole grains. The more variety, color, and texture in your baby’s diet, the better (there are lots of guidelines about safe textures for babies; if you have questions, please comment and ask!). Foods that contain “live and active cultures” (aka probiotics) are great for babies, especially plain unsweetened yogurt. There are some instances where a probiotic supplement may be a good addition to your baby’s routine, but that’s not a one-size-fits-all recommendation. Work with your child’s doctor or an RD to determine if probiotics are a good idea.

When it comes to supplements, the jury is out on what works and doesn’t. Some of the most common that people are using to prevent colds and flu are Vitamin C and elderberry. According to the NIH, the use of Vitamin C supplements might be helpful to reduce the duration and severity of the cold, but won’t keep the cold away completely. The key is that you need to be taking Vitamin C before you get sick; starting a supplement once the cold is in full swing won’t do much. Similarly, elderberry may relieve some symptoms of the flu, but it won’t stave off the pesky illness completely. These supplements aren’t necessarily safe for babies, and you should always read the dosing instructions on any supplement before administering to a child.

So, what’s the bottom line? Initiate solid feeding practices from the start that will allow for lots of different types of plant foods in your baby’s diet. Rely on healthy foods and other evidence-based measures to build immunity rather than supplements. If you have questions about how to feed your baby, please comment below or send me a message!


Claire McCarthy, M. D. (2021, October 12). Boosting your child’s immune system. Harvard
Health. Retrieved December 23, 2022, from

Colostrum: What is it, benefits & what to expect. Cleveland Clinic. (2022, February 21).
Retrieved December 23, 2022, from

How your baby’s immune system develops. Pregnancy Birth and Baby. (2022, May). Retrieved
December 23, 2022, from’s%20immune%20system%20is,last%203%20months)%20of%20pregnancy.

Vitamin C – Consumer (

Elderberry | NCCIH (

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