Children need vitamin D for bone growth and development. So do babies developing in the womb. This is because vitamin D helps us absorb calcium.

Serious vitamin D deficiency can cause rickets, delayed motor development, muscle weakness, aches and pains, and fractures.

Vitamin D deficiency in adults has also been linked to osteoporosis, some cancers, heart disease and diabetes.

If women don’t get enough vitamin D during pregnancy, their children might develop neonatal hypocalcaemia (not enough calcium in the blood) or rickets later in childhood.

Vitamin D and sunlight

You need sunlight on your skin for your body to make vitamin D. You get about 80% of your vitamin D this way.

The amount of sun you need depends on where you live in, and the time of year.

But no matter where you live, you have to be careful about how much sun you get on your skin. Too much sun can lead to sunburn, skin damage and even skin cancer.

Children might be at risk of vitamin D deficiency if they:

  • keep all their skin covered
  • spend most of their time indoors and don’t get much or any sun
  • have a condition affecting how the body controls vitamin D levels – for example, liver disease, kidney disease, problems with absorbing food (such as coeliac disease or cystic fibrosis and some medicines can affect vitamin D levels
  • have darker skin
  • have been breastfed for a long time and have a mother whose vitamin D is low.

Signs of vitamin D deficiency include rickets, delayed motor development, muscle weakness, aches and pains, and fractures.

Treating vitamin D deficiency: 

Talk with your Pediatrician if you’re worried about your child’s vitamin D levels, or you’re pregnant and think you might have low vitamin D.

Your doctor can order a blood test, which is the best way to check vitamin D levels.

For mild deficiencies, your doctor might say that your child needs to get a bit more sun.

If you or your child has a severe vitamin D deficiency, your doctor might say you or your child should take vitamin D supplements, as well as getting more sun.

If you or your child can’t get more sun, the doctor might say that taking vitamin D supplements is the best thing to do. You might take a vitamin D supplement in one large, single dose, or you might take a supplement for several weeks or months.