A study published in the Saudi Medical Journal in 2023, involving 200 infants, revealed that approximately 33% of newborns had low blood levels of vitamin K2 at birth. The study also identified C-section deliveries, prematurity, low birth weight for gestational age, and maternal corticosteroid use before birth as factors increasing the risk of vitamin K2 deficiency in infants. Specifically, infants born via C-section had a 2,5 times higher risk of vitamin K2 deficiency compared to those born vaginally; this risk increased by 3,5 times in premature infants and 4,7 times in infants whose mothers used corticosteroids prenatally.

According to experts, both vitamin D3 and vitamin K2 are involved in calcium metabolism but fulfill distinct roles.

Vitamin D3 enhances calcium absorption from the intestines into the bloodstream and aids the body in synthesizing osteocalcin, a protein involved in bone formation. However, osteocalcin only becomes functional when activated by vitamin K2. Once activated, this protein can bind calcium to bone tissue, thereby strengthening bone mineralization.

Therefore, supplementing only vitamin D3 without ensuring sufficient vitamin K2 can diminish the body's effective utilization of calcium.

The role of vitamin K2 in bone health was also documented in a randomized controlled trial (RCT) published in Nutrition in Clinical Practice in 2026. The study on premature infants showed that supplementing vitamin A (1,500 IU/day) combined with vitamin K2 as MK-7 (50 mcg/day) for 12 months improved bone mineral density in the lumbar spine and femur, while also enhancing height-for-age scores, with high safety recorded.

The first 1,000 days of life are a critical period for a child's skeletal development. Vitamin K2 activates osteocalcin, a protein that binds calcium to bone tissue. Consequently, a deficiency in vitamin K2 can affect bone mineralization. Some studies in premature infants indicate that vitamin K2 supplementation helps improve bone mineral density; however, larger-scale studies are still needed to assess its efficacy across all infants.

How vitamin K2 impacts bone development. Photo: LineaBon K2 + D3

Additionally, infants born via C-section face a higher risk of vitamin K2 deficiency. Unlike vitamin D3, a portion of vitamin K2 is synthesized by the gut microbiota. For vaginally born infants, the passage through the birth canal provides early exposure to the mother's microorganisms, including many beneficial bacteria that synthesize vitamin K2.

In contrast, C-section infants do not undergo this process, leading to slower development of their gut microbiota, with a different bacterial composition primarily derived from the mother's skin and the hospital environment. Analyses of infant gut microbiota have noted lower total menaquinone (vitamin K2) levels in C-section babies compared to those born vaginally.

The amount of vitamin K2 transferred from mother to fetus via the placenta is very limited, and its content in breast milk is also not high. Therefore, many infants, especially those born via C-section or prematurely, are at risk of vitamin K2 deficiency from their earliest days.

Currently, the American Academy of Pediatrics recommends that all infants receive vitamin D3 supplementation at a dose of 400 IU/day immediately after birth. Furthermore, increasing evidence suggests that vitamin K2 plays a supportive role to vitamin D3 in depositing calcium into bones, especially in infants at risk of deficiency, such as those born via C-section or prematurely.

Experts advise that when considering vitamin D3 and K2 supplementation for children, parents should select products with clear origins, fully disclosed active ingredient content, suitable for the child's age, and consult a doctor to choose the appropriate formulation for each specific case.

LineaBon K2+D3 helps support K2 supplementation. Photo: LineaBon K2 + D3

One health supplement product available on the market that helps supplement K2 is LineaBon K2+D3. According to the manufacturer's representative, this product combines vitamin D3 and vitamin K2 as MK7, free from preservatives, alcohol, gluten, lactose, and artificial colors.

LineaBon also uses vitamin D3 ingredients from Lycored (US) and vitamin K2 from Gnosis (France), incorporating Multi-Layer Active Ingredient Lock Technology.

Proactively supplementing D3 and K2 early from infancy is a way to fill "micronutrient gaps" for children. To choose the right type for each baby, parents should consult a doctor.

Yen Chi

The health supplement LineaBon K2+D3 received advertising content confirmation certificate number 1256/2024/XNQC-ATTP from the Food Safety Authority (Ministry of Health) on 19/6/2024. This product is not a medicine and has no therapeutic effect. Its use should follow the guidance of healthcare professionals or doctors.

The unit responsible for importing and distributing the product is An Minh Pharmaceutical Joint Stock Company. Address: number 35, alley 254, Minh Khai street, Mai Dong ward, Hoang Mai district, Ha Noi.

https://www.lineabon.vn/