Whilst having read lots of forum discussion on the importance of vitamin D3 supplementation, and awaiting delivery of my first order, a though struck me.
My mother is 88, housebound for the last 20 years, eats next to nothing containing D3, never sees sunlight and does not supplement.
Apart from her arthritis, her general health is good and she is mentally fully there.
Given that we apparently need @5000iu per day and she is getting next to none, how come she's still around?
Please believe me, I am not being frivolous nor provocative with this enquiry, I am just baffled!
Mike

My grandmother ate lard (animal fat) every day. Pork fat. She cooked with it and even made gravy with it. She drank milk, ate homemade bread, ate eggs and bacon daily. She did not get out much either. She lived until she was 93.

My great-uncle use chewing tobacco daily. He says he used it since he was a teenager. He died at 91. He had no cancer.

I think it is genes. Is it passed on to you? Unknown.

__________________
- Jim
https://www.natmedtalk.com/blogs/jfh

People who eat lard and any kind of meat that is able to get outdoors and benefit from the sun on it's back will have more vitamin D in the fat than indoor finished animals. Lard used to be a reasonable source of vitamin D but is not a reliable source now so many pigs never see the light of day.
Sure it is possible to live without vitamin D.

Having a high vitamin D status improves your cognitive function but many people are not particularly bright to start with so deterioration in cognitive function may not be particularly noticeable.

Having higher vitamin D status improve memory but by the time folks are in their late 80's they may have excellent recall of earlier times but not have the ability to remember what they has for breakfast. Either way it's not particularly critical to life expectancy.

Vitamin D works as an anti inflammatory agent and pain is generally the response to inflammation or the inflammatory response. Thus people with higher vitamin D status use fewer pain medications for a shorter time. So sure you can live a more painful life for a longer period of time with low vitamin D status. But if you've any sense and are not a masochist it's probably a happier less painful option to choose the high road than the low road.

Vitamin d controls your immune function and thus people with higher vitamin D status have higher levels of immunity to infection but the transference of virus or other pathogens depends on circumstances and lifestyle. If your under stress, lead a chaotic lifestyle, are constantly challenging your immune system then it will cave in quicker than people whose immune systems have less trouble to deal with.

The whole point of having a higher vitamin D status is similar to having money in the bank. I've lots of friends/relatives who live perfectly happy lives content in the knowledge they have no cash in the bank, no savings to use in an emergency. The spend what the earn and then keep spending and hope for the best.
I prefer to keep a reserve of cash in an instant access savings account so that what ever happens I know I have sufficient financial resources or insurance to deal with that crisis effectively.
The cost of maintaining an instant access vitamin D reserve is pretty trivial $20 or so should cover it.
There really aren't any risks or drawbacks to keeping your 25(OH)d around the 50ng/ml mark.
Over a lifetime the chances are we are all going to develop cancer.
Those with the Vitamin D3 reserves available at the time the cancer starts proliferating will have the reserves to deal with it. They will never know they had cancer and it disappeared of it's own accord. This is what was found with Breast Cancer screening. A high percentage of people screened and detected in Spring with BC would naturally not have BC in the autumn after a summer of sun exposure.
those who went for chemo surgery or whatever modern medicine could afford to throw at it faired less well than those who simply lay naked in the summer sun. I know what I'd prefer.
Trouble is you never know what's round the corner.
As the cost of being vit d replete is so trivial and the risk so minimal it's better safe than sorry IMO.