I often wonder if these studies are funded by vitamin supplement companies.
Because I am 70 yo. and pre-diabetic I read the article and then went to google for info on Vitamin D.
First, best, and cheapest source of Vitamin D appears to be lying out in the sun naked for a couple of hours per week. It probably means that older people have to stay in the sun longer however since one study shows that absorbtion rates dwindle with age. Of course I may die from skin cancers.
Very few foods in nature contain vitamin D. The flesh of fish (such as salmon, tuna, and mackerel) and fish liver oils are among the best sources [4]. Small amounts of vitamin D are found in beef liver, cheese, and egg yolks
I like and drink a lot of milk and almost all our milk is fortified with Vitamin D. —but I have to change from my average of a gallon per week to a gallon per day.
Or I can eat 3 oz. of fresh sockeye salmon every day which is unlikely on my budget.
Or I can take a tbs of cod liver oil daily.
Or I can reflect on a relatively long and fun life and say to hell with it, everything is a trade off, and I’m not going to ruin my remaining years by living in fear and trying to forestall the inevitable.
How about just a vitamin D-3 supplement?
You should go read some of the stuff at the following website....you’ll probably ensure yourself a longer, healthier life with Vitamin D3 than anything else....
http://www.vitamindcouncil.org/
That's a good general attitude. Life is a series of trade offs, Living in fear of "life" will take years off your life span, without any compensation for it.
That said, supplememts are easy source of vitamins (even if you think it's a placebo, it could be effective, with little potential for harm) and cod / fish liver oil, as well as salmon (and other oily fish such as varieties of tuna or sardines) are good sources of Vitamin D. Canned fish usually contains more vitamins and minerals than prepared for meal otherwise.