I take Vit D with K2 drops - have done for years. I don't understand why people have not been advised years ago to take Vit D, esp in the winter months. It's good for your immune system, your mental health, your bones... Why doesn't every doctor and health advisor advise it?
The only thing I can think of is that Vit D is toxic in high doses, so maybe they think the British public is thick enough to poison themselves? 
It's about time the Gov started telling people to take responsibility for their own health - all this 'Hands, Face and Space' is all very well, but when you get Covid, the only thing that will save you is your immune system! Not the NHS, not the masks, - YOU.
Eat healthily. Stop smoking. Maintain a healthy weight. TAKE VIT D. Get fresh air and exercise.
Make it illegal to spit in public.
The advice given in March to stay indoors, exercise for an hour - WTF? Get the sun on your face. Get fresh air. Get out there. It's the best thing for your Physical and Health health.