Building a lifelong foundation for bone health

The Critical Window of Opportunity

Bones are constantly being formed, remodeled, and reshaped, beginning at the earliest stage in utero and continuing as they grow older in age. During childhood and adolescence, bones tend to grow and develop at a more intensive rate, with up to 90% of peak bone mass acquired by age 18 in females and age 20 in males.^1,2 Providing the proper nutrition, guidance, and vitamins from childhood is important in laying the foundation for good bone health, which will help set them up for the future as their bones continue to develop into adulthood.

“New bone is continuously replacing old bone as the skeleton is constructed and strengthened over time,” explains Samantha Ford, MS, director of business development of AIDP (City of Industry, CA). “Since the bones we build in our youth literally carry us through adulthood, we can support skeletal longevity by providing children with bone health nutrition and guidance.”

The Foundational Duo: Calcium and Vitamin D

Calcium

Calcium comes in several forms, such as carbonate, phosphate, citrate, and gluconate.³Ford explains that each type of calcium differs in percentage of elemental calcium (ranging from 40% to below 10%) and, to a degree, absorption and tolerability in populations with lower levels of stomach acid. To help meet calcium nutrient demands, unique bone health solutions may help reach these goals. As an example, AIDP offers KoACT, a calcium-collagen chelate that mimics the organic bone matrix, which may help deliver collagen along with calcium to support bone flexibility and strength.

Vitamin D

When it comes to vitamin D, the vitamin comes in two forms found in supplements, which are D₂ and D₃.⁴ “Vitamin D₃ (cholecalciferol) is the form produced by the skin when exposed to sunlight and efficiently metabolized by the body. Due to the human body’s native ability to produce D₃, it is typically the preferred supplement form,” says Ford.

For the most part, vitamin D₃ is derived from animal sources such as lanolin, while D₂ typically comes from plant sources, making it a preferred choice of vegans, notes Ford. Vitamin D₂ does have its limitations however. “Although D₂ raises the body’s vitamin D status, it is metabolized differently than D₃, yielding less of the active form,” Ford explains. “This in turn makes D₂ less effective than D₃ at raising blood levels. There are plant-derived D₃ sources such as lichen; however, these have concerns around purity and sustainability.” For its part, AIDP offers a sustainable option calleds VegD3, that is derived from algae and is identical to animal-based D₃, but it is 100% pure and meets U.S. and EU pharmacopoeia.

The Crucial Complement: Vitamin K₂

Vitamin K₂ helps promote bone health through the activation of osteocalcin, an important vitamin K-dependent protein. The vitamin is a crucial complementary nutrient to calcium and vitamin D and helps with the transcellular absorption of calcium.⁵ Once the osteocalcin is activated, the protein binds to the bone mineral matrix. Dr. Stacey Smith, senior medical science liaison, Americas, for Gnosis by Lesaffre, elaborates that this process may help lead to stronger, denser bones. Additionally, Smith expressed one of the challenges children and adolescents experience is that they potentially have sub-sufficient levels of K₂. With low levels, it can impact healthy bone development in their older years.

“Vitamin K-deficient diets place them at risk of not optimizing their ability to develop strong bones (as well as a highly functioning cardiovascular system later in life),” explains Smith. “Despite the widespread availability of a growing number of food products, inadequate K₂ levels persist. Due to the transformation of food habits in developed countries over the last five decades, vitamin K₂ intakes among children have decreased significantly.”

One of the food habits that has changed over the years is milk consumption. Witnessed in school age children and adolescents, less milk in the diet has led to a drop in the intake of calcium and vitamin D.

A 2014 study published in Food & Function, explored vitamin K markers and their levels in bone and the vasculature.⁶ Data was collected from 42 children and 68 adults, where desphospho-uncarboxylated matrix Gla-protein (dp-ucMGP) levels were analyzed. Research showed that children had the highest levels of inactive osteocalcin—8-10x higher than adults—reflecting low vitamin K status and therefore the greatest need for K₂ supplementation. “The higher the peak bone mass a child develops, the more resilient their bones will be later in life.Inadequate bone-building nutrition or deficiencies during the crucial window of development may compromise long-term bone strength, raising the risk for osteoporosis or fractures in adulthood,” says Smith. “Ensuring that children get the right balance of nutrients, physical activity, and lifestyle habits during this period is essential for building lifelong skeletal health.”

Vitamin K₂ and D₃: The Dynamic Duo You Need

Few nutrients work more effectively, harmoniously, than vitamins K₂ and D₃, explains Smith. While K₂ is required to activate K-dependent proteins such as osteocalcin (OC) for bone health and matrix GLA protein (MGP) to inhibit soft tissue calcification, vitamin D₃ is needed for the creation of these proteins. A 2013 clinical trial consisting of 20 children between the ages of 3 to 18 years old, investigated the benefits of supplementing with MenaQ7 K₂ (50 mcg), produced by Gnosis by Lesaffre, and vitamin D (5 mcg calcitriol) daily. Results showed improvements in bone mineral density.⁷

The pairing of vitamins K₂ and D₃ can help ensure that the body is properly utilizing calcium to create stronger, denser bones, while also providing an important role of protecting the body from having the calcium deposit in arteries and soft tissues, which can increase cardiovascular risks. Smith adds that this synergistic scenario makes K₂ a critical partner to vitamin D₃ and calcium, turning bone-supportive nutrition into truly bone-building nutrition.

Formulating for Fun: Making Nutrients Kid-Friendly

Young children have difficulty swallowing pills, which creates a demand for alternative dosage formats.

“As with any child-friendly formulation, taste, ease of use, and tolerability are important considerations. Gummies and chews are continuing to increase in popularity. Challenges here include stability, dose load, taste, and texture,” explains Ford. “For ingredients like D₃ that are heat stable and require a small dose, formulation is less of a challenge. For ingredients that require higher dosages, formats that can easily be incorporated into their typical foods—such as yogurt, smoothies, bars, and beverages—may be more convenient.”

In some cases, the alternative format may even be better than traditional tablets or capsules, depending on the matrix, as well as other ingredients present in the formula. The European Journal of Clinical Nutrition published a study in 2016 that “compared the fasting plasma concentrations of MK-7 from (a) yogurt enriched with MK-7, vitamins D₃ and C, magnesium, n-3 poly unsaturated fatty acids (n-3 PUFA) and fish oil (yogurt Kplus), (b) yogurt fortified with MK-7 only (yogurt K) and (c) soft gel capsules containing only MK-7.”⁸ Healthy men and women between the ages of 45 and 65 years old, were given either yogurt K, yogurt Kplus, or capsules daily. It was discovered in plasma levels that participants consuming the yogurt Kplus had higher levels than individuals that were provided K₂ capsules.

The researchers concluded: “Dairy matrix and nutrient composition may affect MK-7 delivery and improvement of vitamin K status. Yogurt fortified with MK-7 is a suitable matrix to improve the nutritional status of the fat-soluble vitamins.”

Smith explained how vitamin K₂ is quite versatile and can be incorporated into a wide range of delivery systems, from capsules and chewables to liquids, as well as functional gummies.

Conclusion

Ultimately, building strong bones is a lifelong process that begins in utero and continues into young adulthood. Providing children with a strong nutritional foundation during this critical window is essential for their long-term health and can help prevent future issues like osteoporosis and fractures. The right balance of nutrients, physical activity, and healthy lifestyle habits is key. Calcium and vitamin D are foundational for bone health, but they work best when complemented by other key nutrients like vitamin K₂. The synergistic relationship between these vitamins ensures that calcium is properly utilized to build stronger, denser bones while also protecting the cardiovascular system from calcium buildup in soft tissues. By understanding the unique needs of a child’s developing skeleton and providing these essential nutrients in kid-friendly formats, we can help ensure they develop the strong, resilient bones that will support them throughout their entire lives.

References

1. Caradonna, P.; Rigante, D. Bone health as a primary target in the pediatric age. Eur Rev Med Pharmacol Sci. 2009,13 (2), 117-128. Erratum in: Eur Rev Med Pharmacol Sci. 2010, 14 (3), 239-40. PMID: 19499847.
2. van Summeren, M.J.; Braam, L.A.; Lilien, M.R.; Schurgers, L.J.; Kuis, W.; Vermeer, C. The effect of menaquinone-7 (vitamin K2) supplementation on osteocalcin carboxylation in healthy prepubertal children. Br J Nutr. 2009, 102 (8), 1171-1178. DOI: 10.1017/S0007114509382100
3. Calcium. University of Rochester Medical Center. https://www.urmc.rochester.edu/encyclopedia/content?contenttypeid=19&contentid=calcium (accessed Sep 15, 2025).
4. Arnarson, A. Vitamin D2 vs. D3: What’s the difference? Healthline. March 31, 2023. https://www.healthline.com/nutrition/vitamin-d2-vs-d3 (accessed Sep 15, 2025).
5. Abrams, S.A. Bone Health in school age children: Effects of nutritional intake on outcomes. Front. Nutr. 2021, 8. DOI: 10.3389/fnut.2021.773425 (accessed Sep 17, 2025).
6. Theuwissen, E; Magdeleyns, E.J.; Braam, L.A.; et al. Vitamin K status in healthy volunteers. Food Funct. 2014, 5 (2), 229-234. DOI:10.1039/c3fo60464k
7. Ozdemir, M.A.; Yilmaz, K.; Abdulrezzak, U.; Muhtaroglu, S.; Patiroglu, T.; Karakukcu, M.; Unal, E. The efficacy of vitamin K2 and calcitriol combination on thalassemic osteopathy. J Pediatr Hematol Oncol. 2013, 35 (8):623-627. DOI: 10.1097/MPH.0000000000000040
8. Knapen, M.H.; Braam, L.A.; Teunissen, K.J.; Van't Hoofd, C.M.; Zwijsen, R.M.; van den Heuvel, E.G.; Vermeer, C. Steady-state vitamin K2 (menaquinone-7) plasma concentrations after intake of dairy products and soft gel capsules. Eur J Clin Nutr. 2016, 70 (7), 831-836. DOI: 10.1038/ejcn.2016.3