Welcome Moonlight ! I couldn't find anything showing how much D3 or magnesium is in the first product,so I would worry about Vit D overdosing. They usually get enough between meat & sunlight. I do supplement it occasionally but only in the winter when theres less daylight. I think if I was going to buy it rather than make it,I would go with the second site. Personally I just make my own, I use the eggs in the food & grind the shells . Maybe Kaffe can take a look,she's our resident food expert.

The "optimum" Calcium-Phosphorus-Magnesium Ratio as found by Feline Instincts through a 12-yr 'study' on their resident cats is:

Ca:P:Mg = 1.3:1:0.06.

This templae could be used also with dogs --- cats tend to be a little more sensitive to the ratio balance than dogs.

My advice with Vit D supplementation is to be very careful with it and NOT to supplement at all if your dog's serum calcium (yes, Calcium) level is already at the high end of normal... you can precipitate a cascade of trouble.  Vitamin D is not really a "vitamin" as we know it --- it is actually a hormone produced by the kidneys and as with any hormone, one must be careful becuase when one hormone in the body is out of whack, it creates a disturbance in the whole endocrine system - pituitary, thyroid, parathyroid, spleen, adrenal, kidney, liver , etc.

A good way to ensure that your pet has adequate Vit D intake is to feed liver and kidney once a week.  Only when a pet does not eat these foods would I consider vit D supplement - and then just low potency like 400IU per week.

Oh - yes, dogs can synthesize vit D using sunlight, but cats cannot - not to any usable degree at any rate.

RE: vitamin D

I agree with kaffe that I wouldn't pick a calcium supplement with vitamin D added if a multi vitamin is already being used. I've been using 2 multi vitamins tablets to about 5 pounds of food for my cats. The multi vitamins I have are 400 IU vitamin D per tablet.

This site gives 500 IU per kg. of food as the AAFCO standard:

http://www.peteducation.com/article.cfm?cls=2&cat=1661&articleid=662

I've yet to find any source, including AAFCO, that can reconcile the "dry matter" calculation. Simply stated, it doesn't make any sense. Dry is 10% moisture and wet is more like 80%, but pets don't eat 4-5 times as much wet as dry. As close as I could ever tell, ounce for ounce, they eat about the same amount of food whether it's wet or dry. Homemade is basically wet food, but where I've been able to find numbers on supplements, it looks to me that it would be a mistake to calculate homemade on a "dry matter" basis, which would amount to adding on the order of 5 times as much of everything. The AAFCO numbers appear to match other numbers I've been able to dig up if it's calculated on an "as fed" basis.

So, going on that assumption, two multi vitamins, with 400 IU vitamin D each, to 5 pounds of food "as fed", should be pretty close. Maybe just a hair short, but about right figuring 4.4 pounds is two kilos, which would put the vitamin D at about 400 IU per kg. vs. the 500 IU AAFCO recomendation. 2 1/2 tablets would be close to dead on if it's figured that way.

As I remember from looking at people calcium supplements with vitamin D, adding enough of those to get the right amount of calcium would result in way too much vitamin D, especially starting with multi vitamins that have enough without adding extra.

I'd add a disclaimer to this because I'm not 100% confident of my interpretation of the AAFCO charts. As amazing as it may seem, I have yet to find a source that provides pet minimum daily requirements on all vitamins and minerals in the same terms as are available for humans. The argument against providing the information in those terms is dogs vary in size, so the amounts would be a lot different between large and small, but I don't see why it couldn't be expressed on a weight basis. For example, X amount of supplements, per 20 pounds of a pet's weight, per daily serving.

Anyhow, if anyone has better suggestions on how to apply the AAFCO numbers to homemade, I'd be interested in seeing how they calculate it. The recepies I saw at the beginning of the thread that use vitamins and bone meal look to be fairly close to the way I've been figuring it. Comments?

I use to be the "crazy " trying to balance every meal... till I asked the vet a % issue with one of my 1/2 raw 1/2 homemade days recipes ... she  You seriously are not trying to balance every meal perfectly that is next to impossible and well time consuming... she then went on to explain complete and balanced is actually over the course of a MONTH for an animal ...  was me ./// life got much easier;) after that

Don:  I once began a chart comparing what's in my home prepped raw with the nutritonal requirements posted by the NRC, Pitcairn, and a European paper... drove myself nuts... and 5CatMom too  

You're right about the extreme difficulty in calculating anything on a dry matter basis - very confusing... The nutritonal studies now calculate nutrient levels in foods not on DM or "As Fed" but in "Metabolizable Energy (ME)" --- yes --- another unit of measurement to confuse me even further!  Grrrrr....  This is what I am trying very hard to understand to date    I'll let you know if I "crack the code"  hee hee heee heee  It won't be anytime soon

Here are part of the results from that Excel spreadsheet calcs for my 70 lb dog (there are many other numbers, but too long to post them all) - some of this is useful, like the Vit A & D requirements, and if the multi had too much iron:

CALORIES   1741.61   kcal
         
Minerals         
Calcium*                1741.61   mg
Phosphorus   1339.70   mg
Potassium   1875.58   mg
Sodium                351.00   mg
Chloride      535.88   mg
Magnesium   263.92   mg
Iron*      13.40   mg
Copper*      2.68   mg
Manganese*   2.14   mg
Zinc*      26.79   mg
Iodine      396.55   mcg
Selenium   mcg   158.08   mcg
         
Vitamins         
A (RE)      669.85   RE   (have to convert to IU's)
D      6.03   mcg
E      13.40   mg
K      0.72   mg

I agree to a point, but would note that while we eat a lot of different things, pet food is a one size fits all meal that doesn't have a variety factor to catch different things three times a day, over a period of time. I'd lean toward the point of view that every batch doesn't have to be dead on a specific target, but should be fairly close within a reasonable margin of error. I doubt plus or minus 20% would be an issue, but I think a good goal would be to try to hit inside that range.

Thanks to petslave for posting the supplement info. Too bad they don't express the units in IU, where IU is typically used for human values. From what I recall from looking up some related info awhile back, IU isn't a standard conversion factor, but varies depending on the vitamin. Ooof! As others have mentioned, there seems to be a conspiracy to avoid keeping it simple.

Changing tracks to the more practical. I thought I'd toss in the system I worked out for storing batches of food. Scoop it into plain old sandwich bags, and lay them out in a cut down cardboard box that fits on a shelf in the freezer. Here's a pic of what it looks like: