This is from the official Dept Health website - if Jenny Harries thinks differently what would it be doing there, over-ruled by more sensible doctors, perhaps.
"Advice for adults and children over 4 years old
During the autumn and winter, you need to get vitamin D from your diet because the sun is not strong enough for the body to make vitamin D.
But since it's difficult for people to get enough vitamin D from food alone, everyone (including pregnant and breastfeeding women) should consider taking a daily supplement containing 10 micrograms of vitamin D during the autumn and winter.
Between late March/early April to the end of September, most people can get all the vitamin D they need through sunlight on their skin and from a balanced diet.
You may choose not to take a vitamin D supplement during these months.
People at risk of vitamin D deficiency
Some people will not get enough vitamin D from sunlight because they have very little or no sunshine exposure.
The Department of Health and Social Care recommends that you take a daily supplement containing 10 micrograms of vitamin D throughout the year if you:
are not often outdoors – for example, if you're frail or housebound
are in an institution like a care home
usually wear clothes that cover up most of your skin when outdoors
If you have dark skin – for example you have an African, African-Caribbean or south Asian background – you may also not get enough vitamin D from sunlight.
You should consider taking a daily supplement containing 10 micrograms of vitamin D throughout the year. "
Bozo doesnt want to pay for supplements, although they are cheap. The obese are more at risk of vitamin D deficiency btw.