Greeaat....Here goes Isaac with another one of his niacin threads.... 
I’ve seen countless people recommend that niacin can be given in any amount, that you don’t need to worry about them overdosing, they “pee” out the excess. How true really is this, and are their other factors to consider? Aren’t their other ingredients in Cattle B Complex so why aren’t we taking that into account too?
These were some of the questions I had so a did a little bit of research and what I found is the risk is low, but it could overdosed quite easily contrary to popular belief.
According to this study, niacin can have toxic effects when given at 350mg per kilogram, or 150mg per pound. Understand that while chicks do have a much lower niacin requirement, here they are referring to broilers which do have nearly the same or more niacin needs than most ducks.
“Harmful effects of nicotinic acid occur at levels far in excess of requirements. Limited research indicated that nicotinic acid and nicotinamide are toxic at dietary intakes greater than about 350 mg per kg (160 mg per lb) of body weight per day (NRC, 1987). Clinical signs for niacin toxicosis in chicks include reduced egg production, growth retardation, short legs and coarse, dense feathering. High dietary levels of niacin (0.75% to 2.0%) fed to broilers were detrimental to dimensions and mechanical properties of bone (Johnson et al., 1992; 1995; Leeson and Summers, 2001). There was no change in the mineral content of the tibia, but bone strength decreased with increased susceptibility to fracture.”
https://www.dsm.com/markets/anh/en_US/Compendium/poultry/niacin.html
"Note that most Cattle B Complex Vitamins on the market contain around 100mg of niacin per ml"
So really, the chances of overdosing them on natural supplements like Nutritional Yeast or Brewer’s Yeast would be little to none, but administering more than just a couple Ml's to a week old Pekin could have some negative effects, or dissolving a 500mg niacin tablet into a few gallon/s of water and offering it that way.
I also found this regarding niacin overdose in dogs,
"Harmful effects of nicotinic acid occur at levels far in excess of requirements (NRC, 1987). Nicotinic acid and niacinamide tolerance in cats has not been determined. Chen et al. (1938) reported the toxicity of nicotinic acid for dogs. They found that repeated oral administration of 2 g per day of nicotinic acid (133 to 145 mg per kg or 60.5 to 65.9 mg per lb of body weight) produced bloody feces in a few dogs. Convulsions and death followed. Doses of nicotinic acid as great as 0.5 g per day, which is about 36 mg per kg (16.4 mg per lb) body weight, produced slight proteinuria after eight weeks. Nicotinamide is two to three times more toxic than the free acid (Waterman, 1978). "
https://www.dsm.com/markets/anh/en_...he toxicity of,Convulsions and death followed.
So the idea that they can't overdose on niacin is sadly false, more emphasis needs to be put on giving them a correct dose and not just squirting tons of complex into their feed, mouth, or water thinking that "more is really better".
The last thing I wanted to look into was if there would any other ingredients in B complex that could be overdosed just as easy or easier. Here are the Ingredients of this specific brand, but it does seem most that I checked contained the same amounts and ingredients added, and most of the ingredients besides niacin can be given in pretty safe amounts.
"Thiamine Hydrochloride (B1) ..... 100 mg
Riboflavin (B2) ..... 5 mg
Niacinamide - 100 mg
Pyridoxine Hydrochloride (B6) ..... 10 mg
d-Panthenol ..... 10 mg
Cyanocobalamin (B12) ..... 100 mcg"
"A large body of evidence has accumulated that treatment with riboflavin in excess of nutritional requirements has very little toxicity either for experimental animals or for humans (Rivlin, 2006). There are no reports of riboflavin toxicity studies in poultry. Most data from rats suggest that dietary levels between 10 and 20 times the requirement (possibly 100 times) can be tolerated safely (NRC, 1987). When massive amounts of riboflavin are administered orally, only a small fraction of the dose is absorbed, the remainder being excreted in the feces. Lack of toxicity is probably because the transport system necessary for the absorption of riboflavin across the gastrointestinal mucosa becomes saturated, limiting riboflavin absorption (Christensen, 1973). Also, capacity of tissues to store riboflavin and its coenzyme derivatives appears to be limited when excessive amounts are administered "
https://www.dsm.com/markets/anh/en_US/Compendium/poultry/riboflavin.html
Insufficient data are available to support estimates of the maximum dietary tolerable levels of vitamin B6 for poultry. It is suggested, primarily from dog and rat data, that dietary levels of at least 50 times the nutritional requirements are safe for most species (NRC, 1987). Vitamin B6 toxicity causes ataxia, muscle weakness and incoordination at levels approaching 1,000 times the requirement (Leeson and Summers, 2001). Large doses of vitamin B6 can produce detrimental effects in experimental animals and humans. Signs of toxicity, which occur most obviously in the peripheral nervous system, include changes in gait and peripheral sensation (Krinke and Fitzgerald, 1988). Changes in central nervous system function were detected in rats fed excessive vitamin B6 using measurement techniques of startle behavior (Schaeffer, 1993).
https://www.dsm.com/markets/anh/en_US/Compendium/poultry/vitamin_B6.html
"Addition of vitamin B12 to feeds in amounts far in excess of need or absorbability appears to be without hazard. Dietary levels of at least several hundred times the requirement are suggested as safe for most species (NRC, 1987). Vitamin B12 is reported to be toxic with diets of around 5 mg per kg (2.3 mg per lb). Signs of toxicity are unclear, especially with many older reports, since results are likely confounded with toxic effects of fermentation residues, inadvertently included with B12 during manufacture (Leeson and Summers, 2001) "
https://www.dsm.com/markets/anh/en_US/Compendium/poultry/vitamin_B12.html
"Thiamin in large amounts orally is not generally toxic and usually the same is true of parenteral doses (NRC, 1987). In chickens, it takes some 700 times the requirement level of thiamin in order to induce toxicity. Signs of toxicity are blockage of nerve transmissions and labored breathing, with death usually occurring due to respiratory failure."
https://www.dsm.com/markets/anh/en_US/Compendium/poultry/thiamin.html
Also note that I haven't had my morning coffee so there may be a few mistakes here, I'll revise them later.
I’ve seen countless people recommend that niacin can be given in any amount, that you don’t need to worry about them overdosing, they “pee” out the excess. How true really is this, and are their other factors to consider? Aren’t their other ingredients in Cattle B Complex so why aren’t we taking that into account too?
These were some of the questions I had so a did a little bit of research and what I found is the risk is low, but it could overdosed quite easily contrary to popular belief.
According to this study, niacin can have toxic effects when given at 350mg per kilogram, or 150mg per pound. Understand that while chicks do have a much lower niacin requirement, here they are referring to broilers which do have nearly the same or more niacin needs than most ducks.
“Harmful effects of nicotinic acid occur at levels far in excess of requirements. Limited research indicated that nicotinic acid and nicotinamide are toxic at dietary intakes greater than about 350 mg per kg (160 mg per lb) of body weight per day (NRC, 1987). Clinical signs for niacin toxicosis in chicks include reduced egg production, growth retardation, short legs and coarse, dense feathering. High dietary levels of niacin (0.75% to 2.0%) fed to broilers were detrimental to dimensions and mechanical properties of bone (Johnson et al., 1992; 1995; Leeson and Summers, 2001). There was no change in the mineral content of the tibia, but bone strength decreased with increased susceptibility to fracture.”
https://www.dsm.com/markets/anh/en_US/Compendium/poultry/niacin.html
"Note that most Cattle B Complex Vitamins on the market contain around 100mg of niacin per ml"
So really, the chances of overdosing them on natural supplements like Nutritional Yeast or Brewer’s Yeast would be little to none, but administering more than just a couple Ml's to a week old Pekin could have some negative effects, or dissolving a 500mg niacin tablet into a few gallon/s of water and offering it that way.
I also found this regarding niacin overdose in dogs,
"Harmful effects of nicotinic acid occur at levels far in excess of requirements (NRC, 1987). Nicotinic acid and niacinamide tolerance in cats has not been determined. Chen et al. (1938) reported the toxicity of nicotinic acid for dogs. They found that repeated oral administration of 2 g per day of nicotinic acid (133 to 145 mg per kg or 60.5 to 65.9 mg per lb of body weight) produced bloody feces in a few dogs. Convulsions and death followed. Doses of nicotinic acid as great as 0.5 g per day, which is about 36 mg per kg (16.4 mg per lb) body weight, produced slight proteinuria after eight weeks. Nicotinamide is two to three times more toxic than the free acid (Waterman, 1978). "
https://www.dsm.com/markets/anh/en_...he toxicity of,Convulsions and death followed.
So the idea that they can't overdose on niacin is sadly false, more emphasis needs to be put on giving them a correct dose and not just squirting tons of complex into their feed, mouth, or water thinking that "more is really better".
The last thing I wanted to look into was if there would any other ingredients in B complex that could be overdosed just as easy or easier. Here are the Ingredients of this specific brand, but it does seem most that I checked contained the same amounts and ingredients added, and most of the ingredients besides niacin can be given in pretty safe amounts.
"Thiamine Hydrochloride (B1) ..... 100 mg
Riboflavin (B2) ..... 5 mg
Niacinamide - 100 mg
Pyridoxine Hydrochloride (B6) ..... 10 mg
d-Panthenol ..... 10 mg
Cyanocobalamin (B12) ..... 100 mcg"
"A large body of evidence has accumulated that treatment with riboflavin in excess of nutritional requirements has very little toxicity either for experimental animals or for humans (Rivlin, 2006). There are no reports of riboflavin toxicity studies in poultry. Most data from rats suggest that dietary levels between 10 and 20 times the requirement (possibly 100 times) can be tolerated safely (NRC, 1987). When massive amounts of riboflavin are administered orally, only a small fraction of the dose is absorbed, the remainder being excreted in the feces. Lack of toxicity is probably because the transport system necessary for the absorption of riboflavin across the gastrointestinal mucosa becomes saturated, limiting riboflavin absorption (Christensen, 1973). Also, capacity of tissues to store riboflavin and its coenzyme derivatives appears to be limited when excessive amounts are administered "
https://www.dsm.com/markets/anh/en_US/Compendium/poultry/riboflavin.html
Insufficient data are available to support estimates of the maximum dietary tolerable levels of vitamin B6 for poultry. It is suggested, primarily from dog and rat data, that dietary levels of at least 50 times the nutritional requirements are safe for most species (NRC, 1987). Vitamin B6 toxicity causes ataxia, muscle weakness and incoordination at levels approaching 1,000 times the requirement (Leeson and Summers, 2001). Large doses of vitamin B6 can produce detrimental effects in experimental animals and humans. Signs of toxicity, which occur most obviously in the peripheral nervous system, include changes in gait and peripheral sensation (Krinke and Fitzgerald, 1988). Changes in central nervous system function were detected in rats fed excessive vitamin B6 using measurement techniques of startle behavior (Schaeffer, 1993).
https://www.dsm.com/markets/anh/en_US/Compendium/poultry/vitamin_B6.html
"Addition of vitamin B12 to feeds in amounts far in excess of need or absorbability appears to be without hazard. Dietary levels of at least several hundred times the requirement are suggested as safe for most species (NRC, 1987). Vitamin B12 is reported to be toxic with diets of around 5 mg per kg (2.3 mg per lb). Signs of toxicity are unclear, especially with many older reports, since results are likely confounded with toxic effects of fermentation residues, inadvertently included with B12 during manufacture (Leeson and Summers, 2001) "
https://www.dsm.com/markets/anh/en_US/Compendium/poultry/vitamin_B12.html
"Thiamin in large amounts orally is not generally toxic and usually the same is true of parenteral doses (NRC, 1987). In chickens, it takes some 700 times the requirement level of thiamin in order to induce toxicity. Signs of toxicity are blockage of nerve transmissions and labored breathing, with death usually occurring due to respiratory failure."
https://www.dsm.com/markets/anh/en_US/Compendium/poultry/thiamin.html
Also note that I haven't had my morning coffee so there may be a few mistakes here, I'll revise them later.
