Why vitamin D is vital during pregnancy and early childhood

Vitamin D is essential to bone health and there is growing evidence of its important contribution to our health beyond the skeletal system. This article briefly revises vitamin D metabolism, examines the needs of mother and baby and considers the contribution of vitamin D to child bone health.

What is vitamin D?

Vitamin D is a sterol, which has a hormone like activity. As vitamin D can be synthesised through the skin, vitamin D is not a 'true' vitamin (Box 1).

The main source of vitamin D is the sun, although the wavelength required for vitamin D synthesis is not available in Britain from the end of October until April. Dietary sources of vitamin D include salmon, mackerel and other oily fish, eggs and fortified foods such as margarine and breakfast cereals.¹ However, less than
10 per cent of our vitamin D requirement is met through foods.²