Now in place is a population-wide Department of Health recommendation to protect musculoskeletal health, 10 microgrammes (µg) per day, which assumes minimal sun exposure.
Diet typically provides only 24µg per day and daily supplements have been recommended all year round for some groups and suggested during the winter for others.
But what if supplements are not taken?
Careful food choice
As the vitamin is stored in the body, careful food choice combined with modest sunshine exposure during the summer months, avoiding skin damage, may achieve similar results.
This means regular consumption of oily fish, eggs and foods fortified with vitamin D for example, fat spreads.
A two-egg omelette or sandwich provides a third of the daily 10µg target.
Two servings of oily fish
A 140g serving of salmon provides around 10µg and so two servings of oily fish a week will make a substantial contribution.
Lean meat also contains modest amounts of vitamin D and fortified breakfast cereals typically have 3.55µg per 100g.
Looking to the future, the EU-funded ODIN project is exploring various fortification strategies.
- Judy Buttriss is director general of the British Nutrition Foundation