New research has found that vitamin D deficiency in pregnant women is associated with lower peak bone mass in their children years later.
Bone growth during childhood is critical to ensure strong, healthy bones later in life, and reduce risk of osteoporosis when at old age. In childhood, bone formation occurs faster than bone breakdown. After the age of 30, however, this process reverses. Thus it is important to build a lot of bone during childhood and young adulthood.
Vitamin D plays a role in bone health because it helps you to absorb calcium. To date, it’s not clear how much getting enough vitamin D affects your bone density, both early in life and later in life.
It’s also not clear if getting enough vitamin D during pregnancy affects your offspring’s bone health years later in life. In the present study, researchers wanted to examine this, to see if vitamin D levels in women during pregnancy could influence bone mass in their offspring years later.
To do this, researchers conducted a longitudinal, prospective study of 341 mother and offspring pairs from the Western Australian Pregnancy Cohort (Raine) Study.
Serum vitamin D levels were collected at 18 weeks into pregnancy. Bone mineral density (BMD) was measured in the children at 20 years old using dual energy x-ray absorptiometry.
The mean maternal vitamin D level was 22.88 ng/mL, and 38.7% of the women were deficient (defined as <20 ng/mL).
When they looked at vitamin D deficiency in the mothers and compared it to their child’s BMD 20 years later, they found that vitamin D deficiency was indeed associated with lower BMD. Deficient vitamin D levels in the pregnant mother was associated with 1.7% lower total body BMD in their child.
“We conclude that vitamin D deficiency in pregnant women is associated with lower peak bone mass in their children,” the researchers stated. “This may increase fracture risk in the offspring in later life.”
However, since it was an observational study, we cannot conclude if vitamin D deficiency during pregnancy causes lower BMD in children years later. For instance, low vitamin D levels could be a marker for poor overall family health and habits. Future research should clarify the relationship between the two.
Zhu, K., et. al. Maternal Vitamin D Status During Pregnancy and Bone Mass in Offspring at 20 Years of Age: A Prospective Cohort Study. Journal of Bone and Mineral Research, 2013.