Getting Started with Growing Up ® Immunity

Welcome!

This guide introduces you to Begin Health's Growing Up® Immunity.

We developed this daily immune blend with nutrition inspired by breastmilk, nature's original blueprint for immunity, to support your growing kid's immunity, starting with the gut, where an estimated 70–80% of the body's immune cells are found [1].

As kids move through preschool and school-age years, they face constant new germ exposure while their immune systems and gut microbiomes are still developing. Antibiotics, processed foods, and low-fiber diets can add to the strain.

Growing Up ® Immunity gives kids ages 1+ daily nutrition designed to support immune health starting in the gut.

What Growing Up® Immunity Does

Growing Up ® Immunity is an immunity blend designed to support a healthy immune system in growing kids.

It features:

• 2'-FL Human Milk Oligosaccharides (HMOs) – prebiotics found in breast milk that help nourish beneficial gut bacteria and support the gut-immune connection [2, 3].
• effera® Lactoferrin – a bio-identical protein modeled on the lactoferrin naturally found in breast milk that helps support kids' natural immune defenses [4].
• Vitamin D – sourced from plants, essential for a healthy immune response [5].
• Vitamin C – an antioxidant sourced from real acerola cherries that helps keep the immune system strong.

No actual human breast milk is used in Growing Up® Immunity. The HMOs and effera® lactoferrin are both produced using precision fermentation, a process where engineered microbes are used to manufacture proteins and sugars with the same structure as their human counterparts, without using dairy or human milk as a starting ingredient [6, 4].

Growing Up® Immunity helps build immune resilience starting within the gut, with clean, clinically studied ingredients and no added sugar. Because the formula is tasteless and textureless, it mixes easily into water for picky eaters.

Inspired by Breastmilk: The Science Behind Growing Up® Immunity

Breast milk has long been considered the gold standard for infant immune support, and for good reason. It's uniquely rich in HMOs and lactoferrin, two compounds that help train and support a baby's developing immune system from day one [2, 7].

The challenge is that these compounds are incredibly difficult to source at scale. HMOs exist in only trace amounts outside of human milk, and lactoferrin has traditionally been extracted from cow's milk in a form that isn't structurally identical to the human version [6, 4].

That's where science gets interesting. Rather than trying to extract these compounds from milk, scientists can now grow them using precision fermentation, essentially "teaching" engineered microbes to produce the exact same molecule the human body already recognizes [6, 4]. The result is an HMO and a lactoferrin (effera®) that are structurally the same as what's found in breast milk, without using any dairy or human milk as an ingredient.

In practice, that means Growing Up® Immunity is built around the same categories of compounds researchers have spent decades studying in breastfed infants, translated into a daily powder that works for toddlers and kids well past the breastfeeding years.

Growing Up® Immunity doesn't contain breast milk. It's built using precision fermentation to recreate two of breast milk's most studied immune-supportive compounds, HMOs and lactoferrin, in a form kids ages 1+ can take daily.

Why Your Kid's Immune System Needs Support

A few everyday factors make it harder for kids' immune systems to keep up:

• A developing immune system means young kids, especially during high-exposure years like preschool, haven't built up the same defenses as adults.
• Gut microbiome disruptions from antibiotics, processed foods, and low-fiber diets can throw off the gut-immune connection.
• Increased germ exposure comes with daycare, school, and more social contact as kids grow.

These factors can add up to frequent colds, more sick days, and a gut microbiome that needs extra support to bounce back.

Growing Up® Immunity helps address this at the source, supporting the gut microbiome where a large share of immune activity begins [1].

Growing Up® Immunity supports growing kids with a blend of HMOs, effera® lactoferrin, and vitamins D and C.

Whether your kid is starting daycare, heading into cold and flu season, or just needs consistent daily support, Growing Up® Immunity helps build that immune foundation.

What Do HMOs and Lactoferrin Do?

HMOs and lactoferrin are two of the most researched components of breast milk, and both play a direct role in immune development.

• HMOs are the most abundant prebiotic in breast milk. They feed beneficial gut bacteria and help modulate immune responses, and research links HMOs to reduced risk of certain infections in infancy and childhood [2, 3].
• Lactoferrin is an iron-binding protein that supports the maturation of the immune system, activates immune cells like natural killer cells, and has been studied for its role in reducing recurrent respiratory infections in preschool-age children [7, 8].

Research on HMOs and lactoferrin points to long-term support for gut-immune development, not just short-term symptom relief.

What Do Vitamin D and Vitamin C Do?

Vitamin D and vitamin C round out the formula with broader immune and antioxidant support.

• Vitamin D plays a key role in immune regulation, and low vitamin D levels have repeatedly been linked to higher rates of respiratory infections in children [9, 10].

• Vitamin C is a well-known antioxidant that supports overall immune function and everyday resilience.

Research shows children with low vitamin D are more prone to respiratory infections, making consistent daily intake an important piece of immune support [9].

How much does a serving actually provide?

Because kids ages 1–3 take a smaller serving (1 scoop) than kids ages 4+ (2 scoops), the percent daily value (%DV) works out differently by age:

A  younger toddler's single scoop already covers their full daily vitamin C need, while an older kid's two-scoop serving is where vitamin D coverage hits 100%. Both age groups get consistent support daily at levels scaled to their smaller or larger serving size.

Growing Up® Immunity is designed to be taken daily rather than as an occasional immune "boost," consistency matters more than any single dose.

Tips on Getting Started with Growing Up® Immunity

Take daily for best results.

Step 1: Mix & Serve 

• For kids ages 1–3, mix 1 serving into at least 4–6 oz of water.
• For kids ages 4+ and adults, mix 2 servings into at least 8–12 oz of water.

Step 2: Introduce it Gradually

• Start with half a serving and gradually increase to the full recommended amount over several days.

Begin Health Editor's Note:

• Growing Up® Immunity is designed for kids ages 1 and up and is safe for daily, long-term use.
• If your kid is taking any medication or has a medical condition, consult their healthcare provider before starting.
• The product carries a "may contain traces of milk" allergen precaution as a standard manufacturing precaution. The HMOs and effera® lactoferrin themselves are produced through precision fermentation and are not derived from human milk.

Summary

Growing Up® Immunity is a gentle, gut microbiome-focused way to support your kid's immune system, especially during high-exposure years like preschool and the school-age transition. With clinically studied ingredients like HMOs and effera® lactoferrin, plus vitamins D and C, it's an easy, tasteless addition to the daily routine.

These statements have not been evaluated by the Food and Drug Administration. This content is not intended to diagnose, treat, cure, or prevent any disease, and is not a substitute for medical advice from your physician or other medical professional.