A recent study suggests that deficiencies in vitamin D, vitamin K, and calcium may be to blame for a recent increase in low-energy bone fractures in children. These fractures occur in otherwise healthy children and have health care professionals baffled.

For this review, an international team of researchers examined data from a range of studies that addressed environmental and nutritional contributions to children’s bone health. They found that the research showed that the human body requires vitamin K to modify the proteins that transport calcium — and that a lot of people in the Western world are not getting enough vitamin K via diet.

They found that both prepubertal and pubertal age children had high circulating levels of inactive uncarboxylated osteocalcin, which is a vitamin K-dependent protein. High levels of this protein in its inactive form are a sign that a) children aren’t getting enough vitamin K and b) they may be at risk of early onset osteoporosis later in life, due to insufficient bone development.

The researchers recommend that calcium supplements also be taken with fat-soluble vitamin D and vitamin K supplements in order to ensure that the calcium is properly and safely absorbed by the body.

Researchers from Medical University of Bialystok, Poland, led the study. It was published online ahead of print on July 7, 2017, in the Journal of American College of Nutrition.

Previous studies have associated vitamin D with improved lipid profiles in diabetics, lower risk of asthma and allergies in children, reducing the risk of skin damage, reducing the risk of osteoporosis, combating diabetes, lower risk of cognitive decline, and improving age-related macular degeneration. Vitamin D can be found in milk, fortified cereals, fish, and eggs.

Vitamin K2 has been linked to bone and cardiovascular health, as well as a reduced risk of prostate cancer. Vitamin K2 can be found in fermented foods such as cheese but can also be found in meat and soybeans. It is also available in supplement form.

Calcium is best known for its effect on bone health, but previous studies suggest it can also help with weight loss, skin health, and reducing the risk of stroke. Some studies have even suggested that calcium intake is associated with increased longevity.

Calcium absorption decreases as we age, so it is especially important to make sure you are getting enough. While the more common types of calcium come from dairy products, previous studies suggest that algae-derived calcium may in fact be more effective than more common types of calcium.