Hello.

I had a full set of blood tests done recently. Only thing off was low vitamin D. “So I need to get out in the sun more?”, I said to the doctor. “Yep”, said he.

As I understand it, exposing skin to sunlight is a major contributor to production of Vit D in the human body.

So what about other mammals? Especially the furry kind, who have a 24/7 sunblock in the form of their thick fur? Do dogs and cats and such suffer Vit D deficiency, or do they not need it like humans, or do they have other methods of stimulating the production of Vit D?

Also, what about sea-borne mammals, like whales?

esselte said:

Hello.

I had a full set of blood tests done recently. Only thing off was low vitamin D. “So I need to get out in the sun more?”, I said to the doctor. “Yep”, said he.

As I understand it, exposing skin to sunlight is a major contributor to production of Vit D in the human body.

So what about other mammals? Especially the furry kind, who have a 24/7 sunblock in the form of their thick fur? Do dogs and cats and such suffer Vit D deficiency, or do they not need it like humans, or do they have other methods of stimulating the production of Vit D?

Also, what about sea-borne mammals, like whales?

Humans are weird. Other animals don’t have a problem getting it via diet.

AwesomeO said:

esselte said:

Hello.

I had a full set of blood tests done recently. Only thing off was low vitamin D. “So I need to get out in the sun more?”, I said to the doctor. “Yep”, said he.

As I understand it, exposing skin to sunlight is a major contributor to production of Vit D in the human body.

So what about other mammals? Especially the furry kind, who have a 24/7 sunblock in the form of their thick fur? Do dogs and cats and such suffer Vit D deficiency, or do they not need it like humans, or do they have other methods of stimulating the production of Vit D?

Also, what about sea-borne mammals, like whales?

Humans are weird. Other animals don’t have a problem getting it via diet.

Neither should humans.

Plenty of foods have Vitamin D. For example, see:

http://www.healthaliciousness.com/articles/high-vitamin-D-foods.php

I often wonder the same thing about my pet galah. Apart from his feathers, only his claws and around his eyes seem to be exposed to sunlight.

We call him “solar bird” as he seems to perk up after a day outside in the sun.

Speedy said:

I often wonder the same thing about my pet galah. Apart from his feathers, only his claws and around his eyes seem to be exposed to sunlight.

We call him “solar bird” as he seems to perk up after a day outside in the sun.

Feathers may be more interesting than you suspect.

esselte said:

So what about other mammals? Especially the furry kind, who have a 24/7 sunblock in the form of their thick fur? Do dogs and cats and such suffer Vit D deficiency, or do they not need it like humans, or do they have other methods of stimulating the production of Vit D?

Also, what about sea-borne mammals, like whales?

You do know that most mammals get too much sun, don’t you? because unlike humans they don’t wear clothes and live indoors. Evolution usually gives mammals the right colour skin pigment to get the right amount of Vit D.

mollwollfumble said:

esselte said:

So what about other mammals? Especially the furry kind, who have a 24/7 sunblock in the form of their thick fur? Do dogs and cats and such suffer Vit D deficiency, or do they not need it like humans, or do they have other methods of stimulating the production of Vit D?

Also, what about sea-borne mammals, like whales?

You do know that most mammals get too much sun, don’t you? because unlike humans they don’t wear clothes and live indoors. Evolution usually gives mammals the right colour skin pigment to get the right amount of Vit D.

Someone had to say it.

On the other hand, chickens and pigs do live indoors. It’s probably not by accident that domestic fowl and pigs tend to have less melanin in their skin than their wild ancestors.

A possibly-unreliable web source says “Animals and birds covered with fur or feathers may not get much sunlight hitting their skin, but they can make vitamin D in their fur or feathers and then swallow the vitamin D when they groom themselves.”

Another possibly-unreliable web source says that animals can get Vitamin D from “sun-cured hays, forage crops” or in the case of marine animals “fish liver oils” derived presumably from sunlight on algae.

I fort it was vitamin D3, not just vitamin D that was important?

mollwollfumble said:

You do know that most mammals get too much sun, don’t you? because unlike humans they don’t wear clothes and live indoors. Evolution usually gives mammals the right colour skin pigment to get the right amount of Vit D.

If mammals usually have evolutionary adaptations in skin colour to get the right amount of Vit D, in what respect do they get “too much sun”? Are you talking about things which the sun does to mammals other than the Vit D thing?

The number of children diagnosed with rickets is increasing worldwide. This is thought to be a result of children staying indoors and an increase in the use of sunscreen.

Fortunately, as MV mentioned, there are many vitamin D rich foods, plus more foods are fortified with vit D and there are supplemements as well.

re: OP, my budgie is strictly an indoors bird; her seed is fortified with vit D.

Some hairy animals have their sebum convert vitamin D and the self grooming the provides the required intake (except cows, it would appear), others have hair that allow conduction of UV rays to the skin, and then more would get it from diet.

As people age their ability to convert sunlight to vitamin D diminishes and getting enough sun won’t always work.

esselte said:

mollwollfumble said:

You do know that most mammals get too much sun, don’t you? because unlike humans they don’t wear clothes and live indoors. Evolution usually gives mammals the right colour skin pigment to get the right amount of Vit D.

If mammals usually have evolutionary adaptations in skin colour to get the right amount of Vit D, in what respect do they get “too much sun”? Are you talking about things which the sun does to mammals other than the Vit D thing?

Yes, cancers.

> D3

(Checks web)
“Vitamin D refers to a group of fat-soluble secosteroids responsible for enhancing intestinal absorption of calcium, iron, magnesium, phosphate and zinc. In humans, the most important compounds in this group are vitamin D3 (also known as cholecalciferol) and vitamin D2 (ergocalciferol).” “Vitamin D can be found in 2 forms. Vitamin D2 is manufactured by plants or fungus. You would include it through fortified foods such as juices, milk or cereals. However, vitamin D3 is formed when the body synthesizes sunlight on its surface. It mainly occurs through the exposure of animal skin to UVA and UVB rays.” Apparently D2 and D3 have different breakdown products.

Both D2 and D3 are converted in the liver and then kidneys to the hormone calcitriol, which is the biologically active form.

Differences in action of D2 and D3 seem to be most pronounced when excessive doses are taken.