Vitamins - Re-evaluate Your Vitamins Every So Often

Several years ago, Tanna came up anemic in a routine blood test done by my vet. At the time, I was feeding a hodge-podge of vitamins, so I went looking for a single good multivitamin. On the recommendation of another rider, I looked at HorseGuard's Mega-Dose.

I am a numbers girl and I have an extensive spreadsheet set up to evaluate my horses' entire ration for nutrients. I plugged the numbers in for Mega-Dose and was pleased with the overall addition to the rations and was able to replace several supplements I had been feeding. In February 2006, I began to feed the horses 3 oz of Mega-Dose a day.

On a recheck several months after feeding Mega-Dose, Tanna was no longer anemic. Count me happy.

I continued to feed Mega-Dose for years. And continued yearly blood work on all my horses to keep an eye on any anemia problems that might pop up.

In March 2012, Tanna again came up anemic. I was concerned, but gave him Red Cell for a month and a recheck showed him ok. I couldn't just add Red Cell to his ration, though. Red Cell has massive amounts of Vitamin A, as does Mega-Dose. Even his feed (Nutreena XTN and Omolene 100) has some Vitamin A in it.

I finally got around to re-evaluating the rations and to my absolute surprise, Mega-Dose changed formulations somewhere along the way, decreasing the amount per pound of many vitamins and increasing the dosage from 1.5 oz per 500 pounds of animal to a flat 4 oz recommendation.

Here is the Guaranteed Analysis of Mega-Dose as of January 2013 as shown on the Horse Guard website:

And the Guaranteed Analysis from a bucket from 2006 or 2007.

To further belabor the point, I've put the "Per Pound" numbers side by side in the following table to show the changes to the formula. Only 2 values increased. One was Biotin to a nice 128 mg per pound instead of 85.28 mg per pound. The other was the addition of Magnesium. Every other number dropped some or even significantly.

Nutrient	Measure	Mega Dose 2006 (1 lb)	Mega Dose 2013 (1 lb)	Difference
Biotin	mg	85.28	128.00	42.72
Calcium	g	3.73	2.80	-0.93
Choline	mg	667.00	500.00	-167.00
Cobalt	mg	16.00	12.00	-4.00
Copper	mg	800.00	300.00	-500.00
Folate (Folic Acid)	mg	9.80	8.00	-1.80
Iodine	mg	10.60	8.00	-2.60
Iron	mg	2,132.00	400.00	-1,732.00
Lysine	g	3.73	2.50	-1.23
Magnesium	g	0.00	0.70	0.70
Manganese	mg	935.00	0.70	-934.30
Pantothenic acid (B5)	mg	107.00	80.00	-27.00
Phosphorus	g	3.00	2.50	-0.50
Riboflavin (B2)	mg	117.00	88.00	-29.00
Selenium	mg	28.60	12.00	-16.60
Thiamin (B1)	mg	67.00	50.00	-17.00
Vitamin A	IU	266,500.00	200,000.00	-66,500.00
Vitamin B12	mg	0.40	0.30	-0.10
Vitamin B6	mg	80.00	60.00	-20.00
Vitamin D	IU	21,320.00	16,000.00	-5,320.00
Vitamin E	IU	10,666.00	5,000.00	-5,666.00
Zinc	mg	2,132.00	800.00	-1,332.00
Vitamin C (absorbic acid)	mg	675.00	510.00	-165.00
Methionine	mg	24,000.00	2,500.00	-21,500.00

I am very annoyed at myself for not catching this sooner and I honestly don't know when the formula changed.

I guess the lesson for me is to re-evaluate the ration every so often to be sure something hasn't changed.

As a result of this discovery, I have decided to discontinue use of Horse Guard's Mega-Dose and go with a different option.

I'd love to hear what your favorite multi-vitamin is as I research new options for my horses.