One cup, measuring roughly 237ml, of fortified orange juice with breakfast can start your day off with up to 100 IU of vitamin D, or 12 percent of the recommended daily value.
Fortified food and drinks, such as orange juice, have additional nutrients added to them and are designed as an easy way to help increase the recommended daily value of vital vitamins.
Ms Richards said: “You can also find good sources in fortified foods, like fortified breads, cereals and orange juice.”
Dr Perry pointed out that some yoghurts are also fortified to include more vitamin D.
He added that “oily fish such as salmon, sardines, herring and mackerel, red meat, liver, egg yolks” are other great sources of naturally occurring vitamin D.