Many children have teeth that are practically falling apart due to weak enamel. Now researchers have studied whether a lack of vitamin D during pregnancy could be the culprit.

Tooth enamel is the body’s hardest substance, but some children have tooth enamel that is far from hard enough.

A study in the British Dental Journal reports that up to one in six children globally is affected.

Weak enamel is often discovered when the baby teeth fall out, and the adult teeth start to erupt. The weak enamel can appear as white and yellow-brown spots on molars and incisors in some children. In others, the teeth might be partly brown, with a rough surface. Some children are especially seriously affected and develop weak enamel on many teeth.

“It’s complicated to find treatment for these children. The fillings adhere less well and often fall out. Some children have to have their adult molars pulled at a young age because their teeth are in such bad shape,” says Torunn Børsting, a PhD candidate at NTNU and project coordinator at the Dental Services Competence Center in Central Norway (TkMN).

However, research suggests that bad teeth are caused when the forming of the enamel has been disturbed.

The formation of enamel is a complicated process that takes place over many years and begins during the foetal stage. Strong enamel contains lots of minerals, almost 99 per cent. Weak enamel contains few minerals and more water and protein.

A researcher from Kings College in London has found that these children visit the dentist ten times more often than other children do.

Several studies have investigated the connection between vitamin D and enamel defects. Torunn Børsting, a PhD candidate at NTNU, carried out a study over several years, but because some of the mothers withdrew along the way, it could not be established statistically that vitamin D during pregnancy was the culprit.

Torunn published a study in which she checked vitamin D deficiency in the mother during pregnancy as a cause.

Vitamin D plays an important role in the absorption of calcium and phosphate in both teeth and bones.

The study was carried out over seven years. First, 176 pregnant women were examined twice during pregnancy to check their vitamin D levels. After seven years, the children were called in to check their teeth. They were between seven and nine years old when the dental health exams were carried out.

Børsting’s main theory was that if the children were born with a low level of vitamin D, it might be more difficult to increase the level enough after birth, as compared to children who start life with an adequate level of vitamin D.

The study showed that 32 per cent of the children had at least one six-year molar with enamel defects. A connection was also found between the mothers who had low levels of vitamin D during pregnancy and enamel defects in children.

Several studies have investigated the connection between vitamin D and enamel defects. In a study from Denmark, pregnant women were given supplements with vitamin D during pregnancy, which resulted in clearly fewer children with developed enamel defects.

But Torunn notes that a study from the Netherlands, in which vitamin D was measured in the mother during pregnancy but which provided no supplements, did not show a connection between vitamin D and enamel defects.