I cant edit my original post, so the rest is below.

http://news.bbc.co.uk/1/hi/health/7083323.stm

The sleep hormone melatonin increases the release of mesenchymal stem cells, and is also more effective as an antioxidant than say Vitamin C amongst other things.
http://www.ncbi.nlm.nih.gov/pubmed/24650016
http://www.benbest.com/nutrceut/melatonin.html#aging

A book called A Million of Facts by Sir Richard Philips published around 1839 states on page 148 "Riley asserts that Arabs, in the desert liver for 200 years."

Lots of UVB in the desert!

The Welcome Trust in Aug 2010 stated there are 2,776 binding sites for the Vitamin D Receptor in the Human Genome, most of which are concentrated around the immune system genes.
https://wellcome.ac.uk/press-release/vitamin-d-found-influen...

Yes genes can change in the body.

Water Fasting is also the other major factor in long life as your lysosomal enzymes come into play.
https://en.wikipedia.org/wiki/Lysosome

Some people have stated that military medical experiments on fasting carried out around the time of WW2 to learn how best to deal with starved prisoners of war, have shown moles on the skin have shriveled up and disappeared, and grey hair has also returned to its natural colour amongst other rejuvenating effects. A variety of studies have shown improvements in the body, ranging from increased spatial intelligence (ghrelin the hunger hormone) to better survival rates when undergoing various cancer treatment protocols. Loads can be found using google scholar, but heres just one recent example.

http://www.telegraph.co.uk/science/2016/03/12/fasting-for-th...

On the point of lysosomal enzymes, if fasting, once the body has digested the food in the digestive tract usually 3 days, around day 3-5 it goes into a ketogenic state, in fact a ketogenic diet is sometimes used in cancer treatments to increase the effectiveness of the protocol, although it certainly helps deal with the toxic side effects of some protocols.

http://stm.sciencemag.org/node/186102.full

Interestingly some lysosomal enzymes are only activated after 10 days of fasting, today how many people fast for this length of time?

I cant help but notice some parallels with Lent, in the distant past before modern medicine, Lent was about fasting, today its only about giving up something for a period of time. I also cant help but notice that when Jesus was crucified, he would have been effectively fasting on the cross whilst also being exposed to copious amounts of sunshine leading to an increase in Vit D, although the nitric oxide is the most notable short term effect as it takes Vit D about 14 days to become activated in the body afters its been processed by the kidney's and liver where all your fat soluble vitamins are stored.

After Jesus was taken down from the cross, and banged up in a dark cave, melatonin would have increased effectively helping him to come back from the dead!
Bear in mind modern medicine was around back then so whilst it can only be considered supposition, there are some circumstances which could have certainly brought him back from the dead, if he wasnt really in a deep coma.

Numerous instances of people coming back from the dead even today occur which get classed as miracles and some mammals will fast if they dont feel well.

Before anyone rushes off to try to fast, there are some precautions you should undertake. Namely never get cold, cold is a very effective killer when fasting. You also need to increase your Vit A intake, best source is eating liver, and whilst some might caution against taking too much Vit A, UV will destroy Vit A in the skin, and zinc binds the Vit A in the liver into something called Retinol Binding Proteins, which then moves to other parts of the body, improving things like the mucous membranes in the digestive system, lungs and elsewhere. In a way Vit A will improve the digestive system helping your body to absorb more of what it needs from the food you consume, so is a good place to start. Vit A primarily benefits the innate immune system which is what keeps you alive in your final years, Vit D benefits the adaptive immune system.

I think its also interesting that animals whose habitats are closest to the poles have the highest levels of Vit A in their body, yet those living near the equator have the highest levels of Vit D.

Its also worth pointing out that as more people no longer work the land but are indoors so much, one could argue that todays lifestyles are not always so good for us.

Take this study.
https://www.vitamindcouncil.org/blog/washing-away-vitamin-d/

In the old days, its routine to just wash your pits, feet and groin and have a bath once a week. Today everyone showers. Its also worth pointing out that we can absorb ions through the skin, more so in those regions where we sweat the most, but we see examples of this from things like nicotine patches, mag oil (magnesium chloride mixed with water) as well as Epsom salt baths (magnesium sulphate) although the body will excrete sulphate faster than chlorides. Magnesium and zinc are very useful for Vit D, as there is a zinc finger on the Vit D Receptor.

I could go on, I've read hundreds if not a few thousands of studies for over a decade now on this subject, but you have the most important info here. However like everything no one thing is a panacea, so even if you do get enough Vit D, if you dont have enough Mg or Zn as a couple examples, you are not neccesarily getting the full benefits. Coupled with todays more toxic polluted lifestyles millennials will not live as long as those born around the end of the 18th and 19th century which data today is now starting to suggest.

Even Vitamin RDA's which came into existence around the 1950's are set so low as to only help prevent the worst of illness, eg Vit D RDA @ 400ui is generally enough to prevent rickets, Vit C just enough to prevent scurvy, iodine just enough to prevent goitre's as a few off the top of my head.

I'm just a programmer not medically trained but I can read and apply logic and questions to studies I have read whilst I wait for the compiler to complete, but I dont suffer from Milgrams obedience to authority though, so I question everything.

Check out Fasting by the Hygienists for more info on fasting, for a starting place or even find out about the Fasting Olympics which took place around the 1900's, the 1903 one took place in New York, and dont be tempted to overdose on some vitamins, as some chemicals classed as vitamins are toxic if consumer above the RDA levels, Nicotinamide (Vit B3) being one such when compared to the safer form Niacin, although getting your B vits from liver is best as digested slowly.

Worth noting that most man made vitamins in pill form will behave in the same way as medicines/drugs as noted in this article.
http://www.smithsonianmag.com/smart-news/we-used-recycle-dru...

So there is some truth in what Dr's used to say when they said "you are what you eat".