Plant Protein Diets Research Articles

Determination of the Effects of Fish vs Plant vs Meat Protein-based Diets on the Growth and Health of Rainbow Trout

Rahnema, S., Borton, R. and Shaw, E. 2005. Determination of the effects of fish vs plant vs meat protein-based diets on the growth and health of rainbow trout. J. Appl. Anim. Res., 27: 77–80. One hundred eight fingerling rainbow trout were used in an experiment to compare feed consumption, growth rate, gain-to-feed efficiency and live and carcass characteristics for rainbow trout receiving diets containing fish meal (FM), plant protein (PP), or feather meal and meat meal (FMMM), based diets. Six trout were housed in an 18″ × 18″ × 22″ cage (18 total cages) and nine of these cages (three per treatment) were placed in each of two 1000-gallon tanks. Fish were fed twice per day all the feed that they would eat within 30 min. Feed consumption and fish weights (by cage) were measured once every other week. At the end of the feeding trial, one fish from each cage was harvested, frozen in water and stored at −25C. The left half of each trout was excised, wrapped in aluminium foil and baked in an oven at 163C for 30 min. The trout were then divided into approximately 1.0 cm 3 cubes (about 20 g) and presented to the panel for evaluation of flavour, off flavour, tenderness, juiciness and overall acceptability of the meat. The right half of each trout was excised and used for laboratory analyses of moisture, fat, ash and protein content. The Ca content of the PP was lower than FM and FMMM diets. Fish consuming the PP diet had consumed less feed (P<0.00) and had a lower average daily gain (P<0.02) than the fish on FM or FMMM diets. Feed-to-gain ratios for PP and FM diets were similar and both were lower (P<0.00) than that of the FMMM diet. There were no differences due to treatment for moisture, fat, crude protein or ash content of the trout. Trout fed the FM diet were juicier and tenderer than the trout fed the PP diet. It is concluded that a meat scrap ration may substitute for the commercial fish meal ration if it is economically available.

Nutritional assessment of somatolactin function in gilthead sea bream ( Sparus aurata): concurrent changes in somatotropic axis and pancreatic hormones

The role of somatolactin (SL) in the regulation of energy homeostasis in gilthead sea bream ( Sparus aurata) has been analysed. First, a down-regulation of plasma SL levels in response to gross shifts in dietary amino acid profile and the graded replacement of fish meal by plant protein sources (50%, 75% and 100%) has been observed. Thus, the impaired growth performance with changes in dietary amino acid profile and dietary protein source was accompanied by a decrease in plasma SL levels, which also decreased over the course of the post-prandial period irrespective of dietary nitrogen source. Secondly, we examined the effect of SL and growth hormone (GH) administration on voluntary feed intake. A single intraperitoneal injection of recombinant gilthead sea bream SL (0.1 μg/g fish) evoked a short-term inhibition of feed intake, whereas the same dose of GH exerted a marked enhancement of feed intake that still persisted 1 week later. Further, we addressed the effect of arginine (Arg) injection upon SL and related metabolic hormones (GH, insulin-like growth factor-I (IGF-I), insulin and glucagon) in fish fed diets with different nitrogen sources. A consistent effect of Arg injection (6.6 μmol/g fish) on plasma GH and IGF-I levels was not found regardless of dietary treatment. In contrast, the insulinotropic effect of Arg was found irrespective of dietary treatment, although the up-regulation of plasma glucagon and glucose levels was more persistent in fish fed a fish meal based diet (diet FM) than in those fed a plant protein diet with a 75% replacement (diet PP75). In the same way, a persistent and two-fold increase in plasma SL levels was observed in fish fed diet FM, whereas no effect was found in fish fed diet PP75. Taken together, these findings provide additional evidence for a role of SL as a marker of energy status, which may be perceived by fish as a daily and seasonal signal of abundant energy at a precise calendar time.

Incorporation of a mixture of plant feedstuffs as substitute for fish meal in diets of juvenile turbot ( Psetta maxima)

A study was designed to evaluate the maximum level of substitution of fish meal in diets for turbot when a mixture of feedstuffs of plant origin was used and when the amino acid profile was adjusted to reflect amino acid profile of a reference fish meal based diet. Five diets were formulated: a reference diet (FM40) containing 40% fish meal and four other diets (FM30, FM20, FM10 and FM0) in which protein from fish meal was substituted by protein from lupin, corn gluten and wheat gluten meal. Amino acids profile of each diet was balanced by addition of crystalline amino acids. Turbot, initially weighing 26 g were fed these diets for 12 weeks and growth parameters were recorded. Protein (96%), energy (83%) and dry matter (73%) digestibility were very high in all diets tested. Feed intake was significantly decreased by the incorporation of plant protein in diets (from 10.2 g/kg ABW/day to 8.2 g/kg ABW/day in fish fed diets FM40 and FM0, respectively), growth rate was only affected in fish fed diets FM10 and FM0 (respectively, 2.2 and 1.9%/day against an average of 2.4%/day for the other treatments) and no effect on feed utilisation was observed. The whole body composition of fish and the nitrogen retention were significantly negatively affected when dietary fish meal incorporation was equal or less than 20% diet. Activities of alanine amino transferase (ALAT) were significantly increased by the dietary incorporation of plant protein. These results suggest that a sizeable amount of fish meal can be replaced by plant feedstuffs in diets of turbot when an adequate mixture of plant feedstuffs along with amino acid supplementation are used.

Effect of dietary protein and lipid source on the growth, survival, condition indices, and body composition of marron, Cherax tenuimanus (Smith)

A trial was conducted in 12 purpose-built, commercial, drainable, earthen ponds to evaluate the effect of fish and plant protein and lipid source on the growth, condition indices, and body composition of marron ( Cherax tenuimanus). Juvenile marron (1.3 ± 0.28 S.E. g) at the stocking densities of three per square meter were fed for a period of 1 year with four different formulated isoenergetic practical diets (D 1, D 2, D 3, and D 4). Three of the test diets (D 1, D 2, and D 3) were isonitrogenous whereas the fourth test diet (D 4) was protein-free. Protein and lipid sources in D 1 were from Lupin ( Lupinus albus) whereas protein and lipid sources in D 2 and D 3 were from fish meal. Fish oil (3.5%) was added to D 1, D 3, and D 4 whereas sunflower oil was added to D 2 and D 4 in order to make them isoenergetic. The four test diets were randomly allocated to three replicate ponds. The lack of protein in D 4 did not significantly influence ( P > 0.05) the mean final weight andspecific growth rate of marron. Survival was low in all ponds (13.82–34.66%) but feeding with D 4 resulted in a significantly ( P < 0.05) higher survival than marron fed with D 1 and D 2. Feeding a diet containing a combination of fish protein and fish oil (D 3) resulted in significantly higher ( P < 0.05) wet tail muscles-to-body weight ratio than was observed with other diets. Tail muscles protein level of all marron was significantly lower ( P < 0.05) at the end of the trial than at the beginning. EPA and DHA in hepatopancreas and tail muscles of marron were affected by the four test diets. The inclusion of plant protein in formulated diets had a negative impact on the pond environment due to significantly higher unionised ammonia levels that resulted in lower survival. Juvenile marron fed with a plant protein diet had significantly lower protein levels in their hepatopancreas compared to those fed with diets containing animal protein. Feeding marron with lupin protein source (D 1) and plant oil (D 2) for 1 year did not alter the lipid content of their hepatopancreas. Four test diets had no influence on the fat content of marron hepatopancreas; however, these test diets significantly reduced the protein content of the tail muscles of marron. Environmental variables, particularly temperature, nitrogen metabolites, and the natural productivity of the ecosystem, greatly influenced the nutritional requirements of the juvenile marron under culture.

Dietary Animal and Plant Protein and Human Bone Health: A Whole Foods Approach

Urinary calcium excretion is strongly related to net renal acid excretion. The catabolism of dietary protein generates ammonium ion and sulfates from sulfur-containing amino acids. Bone citrate and carbonate are mobilized to neutralize these acids, so urinary calcium increases when dietary protein increases. Common plant proteins such as soy, corn, wheat and rice have similar total S per g of protein as eggs, milk and muscle from meat, poultry and fish. Therefore increasing intake of purified proteins from either animal or plant sources similarly increases urinary calcium. The effects of a protein on urinary calcium and bone metabolism are modified by other nutrients found in that protein food source. For example, the high amount of calcium in milk compensates for urinary calcium losses generated by milk protein. Similarly, the high potassium levels of plant protein foods, such as legumes and grains, will decrease urinary calcium. The hypocalciuric effect of the high phosphate associated with the amino acids of meat at least partially offsets the hypercalciuric effect of the protein. Other food and dietary constituents such as vitamin D, isoflavones in soy, caffeine and added salt also have effects on bone health. Many of these other components are considered in the potential renal acid load of a food or diet, which predicts its effect on urinary acid and thus calcium. "Excess" dietary protein from either animal or plant proteins may be detrimental to bone health, but its effect will be modified by other nutrients in the food and total diet.

Effect Of Animal And Plant Protein Diets On Growth And Fecundity In Ornamental Fish, Betta Splendens (Regan)

The effects of different levels of animal and plant protein (10%, 15%, 25%, 35% and 45%) on growth and fecundity in Siamese fighting fish, Betta splendens, were tested over a period of 154 days. Fish fed 35% animal or plant protein had the highest mean body wet weight, growth rate, gonad weight and fecundity than any other tested level. Animal protein induced gonad develop- ment earlier than plant protein. Female B. splendens fed the 35% animal protein diet had a 79% higher gonad weight (87 mg wet weight) than those fed the diet with the same level of plant pro- tein (49 mg wet weight). Spawning trials showed that 35% animal or plant protein diets produced the highest number of eggs and the highest hatching rate compared to the other diets; hence, 35% animal or plant protein is considered the optimum level for B. splendens. Females fed the 35% animal protein diet laid 1044 eggs in three spawnings in contrast to 846 eggs produced by fish fed the 35% plant protein diet. The necessity of incorporating an optimum level of animal protein in the diet for maximum reproductive performance in B. splendens is discussed.

Diet development and evaluation for juvenile abalone, Haliotis asinina: animal and plant protein sources

Growth studies were conducted to determine the suitability of animal and plant protein sources in the diet of abalone, Haliotis asinina. Juvenile abalone with mean initial weight and shell length of 0.69±0.04 g and 11.4±0.35 mm, respectively, were fed practical diets for 84 days at a temperature range of 28–31 °C. The practical diets contained 27% crude protein from various sources such as fish meal (FM), shrimp meal (SM), defatted soybean meal (DSM), and Spirulina sp. (SP). A formulated diet (diet 1) served as the control. The diets were fed to abalone at 2–5% body weight once daily at 1600 h. Weight gain (WG), increase in shell length (SL), specific growth rate (SGR), protein efficiency ratio (PER) and feed conversion ratio (FCR) were evaluated. Highest weight gain (WG: 454%) was attained with abalone fed diet 2 with protein sources coming from a combination of FM, SM, and DSM. This value was, however, not significantly different ( P<0.05) from those fed diets 4 and 1 (Control diet) with protein sources coming from FM, SM, SP and FM, DSM, SM, respectively. Abalone fed diet 3, which used both plant protein sources, DSM and SP, showed significantly lower WG (327%). Survival was generally high ranging from 85% to 100% for all treatments. The SGR showed the same trend as the percent weight gain. The FCR and PER obtained, however, were not significantly different for all treatments. The amino acid profile of diets 1, 2, and 4 simulated that of the abalone protein, which could have been a contributing factor to the higher growth rate of abalone fed these diets. Diet 3, which contained only plant protein sources, showed relatively lower methionine values compared with the abalone muscle tissue. Although abalone are considered herbivorous animals, results of this study indicate that a combination of dietary plant and animal protein sources was necessary to attain the best growth rate.

Storage proteins.

Plants accumulate storage substances such as starch, lipids and proteins in certain phases of development. Storage proteins accumulate in both vegetative and reproductive tissues and serve as a reservoir to be used in later stages of plant development. The accumulation of storage protein is thus beneficial for the survival of plants. Storage proteins are also an important source of dietary plant proteins. Here, we summarize the genome organization and regulation of gene expression of storage protein genes in Arabidopsis.

EFFECT OF DIETARY PROTEIN SOURCE ON GROWTH OF OREOCHROMIS NILOT/CUS

reochromis niloiicus fingeriings with initial body weight and length ranging from 20 to 39.5g and from 10 to 13.5cm., respectively .were reared in two cement ponds at a density of 4 fish/m". The two cement ponds were divided into five equal divisions (partitions) by nets. Fishes in each partition were fed on one of the experimental diets at 3% of body weight 6 times a week for a period of 130 days. This research was carried out at Al-Kanater AL-Khayria Fish Research Station to study the effect of dietary protein sources on growth of O. niloticus. Growth rate, average daily gain, specific growth rate and feed conversion ratio were determined. The results indicated that the highest growth rate (0.86), highest specific growth rate (0.96), maximum weight gain percentage (250.6%) and the lowest feed conversion ratio (2.37) were obtained for fish fed the formulated diet containing 25% protein, whereas the opposite was found for fish fed wheat bran alone. Results also showed that animal protein diet was better than plant protein diet for tilapia feeding. From the economical point of view,the results indicated that the balanced diet containing 20% protein was the most suitable diet for fish feeding in the cement ponds.

Diets With Either Beef or Plant Proteins Reduce Risk of Calcium Oxalate Precipitation in Patients With a History of Calcium Kidney Stones

Objective To determine the effect of substituting equal amounts of dietary protein as animal protein (beef) for plant protein (legumes, seeds, nuts, and grains) on urinary components associated with calcium oxalate precipitability risk.Design Randomized crossover trial.Subjects Twenty-three normocalciuric patients with a history of calcium kidney stones (8 women and 15 men, mean age 50.7±14.6 years) with 24-hour urinary calcium ≤10.3μmol, 24 hour urinary oxalate excretion between 228 and 963μmol, and a urinary calcium increase of ≤1.0μmol in 4 hours after a 25μmol oral calcium load.Setting Four-day, free-living adaptation period, followed by 2-day metabolic unit study.Intervention The study compared consumption of 2 servings of beef (43g protein for women and 50g for men) daily with an equal amount of protein from plant foods including legumes, nuts, and grains.Main outcome measures Tiselius risk index (TRI) for calcium oxalate precipitability calculated from urinary calcium, oxalate, magnesium, citrate, and volume.Statistical analyses Paired t tests.Results Urinary calcium, oxalate, magnesium, citrate, phosphorus, volume, and TRI did not differ between diets. Urinary sodium and potassium were higher for patients on the plant protein diet. After correcting for variations in urinary sodium and potassium between diets, the difference in urinary calcium remained insignificant. TRI was lower on both beef- and plant-protein diets compared with self-selected prestudy diets for all participants.Conclusion/Applications Balanced diets containing moderate amounts of either beef or plant protein are equally effective in reducing calcium oxalate kidney stone risk based on changes in urinary composition. J Am Diet Asoc. 2001; 101:326-331.

Effect of dietary plant and animal protein intake on sperm quality in monkeys.

This study was conducted to evaluate the influence of animal and plant protein diets on sperm quality indices over 120 days, using the vervet monkey (Cercopithecus aethiops), as a model. These experiments were divided into a 60-day period of high-protein consumption (+/-17% crude protein), followed by a 60-day term of sustainable protein intake (+/-9% crude protein). All the diets were designed to be similar, except for the source of dietary protein that the animals consumed. High-protein diets containing milk solids or maize + legumes had no significant effect on sperm quality parameters over the first 60 days. During the next 60 days of the investigation, sustainable plant and animal protein diets had differential effects on a number of sperm quality indices. When compared to the plant-based diet, the monkeys that were given the animal protein diet containing milk solids had lower sperm counts (p < .04), reduced sperm motility (p = .04), higher sperm midpiece abnormalities (p < .05), and a trend (p = .10) towards increased sperm head defects. These findings shed some light on the impact of variable dietary proteins on sperm quality, but should be followed by longer-term investigations around this important reproductive health issue.

Effects of animal or plant protein diets on cecal fermentation in guinea pigs ( Cavia porcellus), rats ( Rattus norvegicus) and chicks ( Gallus gallus domesticus)

Monogastric herbivores such as the guinea pig depend on energy supply from enteric fermentation as short-chain fatty acids (SCFA) corresponding to 30–40% of their maintenance energy requirements. They evolved specific digestive system to adapt their indigenous microflora to plant polysaccharides fermentation. No information has been available about the adaptability of microbial fermentation in hindgut of the monogastric herbivorous to an animal protein diet. We investigated if the guinea pig can fully retrieve energy of an animal protein diet by hindgut fermentation compared with a plant protein diet. For comparison, we also studied two omnivores. End products of in vitro cecal fermentation (SCFA, ammonia and gases) were measured to judge how well an animal protein diet could be fermented. The animal protein diet resulted in the less intensive fermentation with increased feed intake and volume of cecal contents than the plant protein diet only in guinea pigs. This may be due to a limited capacity of the hindgut microflora to adapt to the substrate rich in animal protein. We also found that chick cecal contents produced methane at higher emission rate than ruminants.

Growth, feed utilization and carcass composition of catfish Clarias batrachus (Linn .) fingerlings fed on dried fish and chicken viscera incorporated diets

A 30-day feeding trial was conducted to evaluate dried fish and chicken viscera, and a combination of oil cakes as complete substitutes for fish meal in the diet of catfsh Clarias batrachus (Linn.) fingerlings. Triplicate groups of fingerlings with a mean initial body weight of 2.0 g were each fed four isonitrogenous diets at 4% of wet body weight. Performance of the diets was judged on the basis of feed acceptability, body weight gain, feed conversion ratio and protein efficiency ratio. A significant increase (P < 0.05) in body weight gain, protein efficiency ratio and a decreased feed conversion ratio (P < 0.05) was observed in fish fed on fish meal, followed by fish viscera, chicken viscera and only plant protein incorporated diets. Although inferior to fish meal and dried fish viscera, growth and feed utilization responses of fingerlings fed on dried chicken viscera and plant protein diets were similar. The fish accumulated a significantly greater (P < 0.05) amount of fat (18.3%) in the body carcass when fish viscera was incorporated in the diet. The study revealed that satisfactory growth and feed utilization responses could be achieved through replacement of fish meal by dried fish and chicken viscera in the diet of catfish fingerlings.

Dietary substitution of soy and rapeseed protein concentrates for fish meal, and their effects on growth and nutrient utilization in gilthead seabreamSparus aurataL.

Soy and rapeseed protein concentrates (SPC and RPC) were evaluated as fish meal substitutes in gilthead seabream Sparus aurata L. diets. The protein concentrates were used to replace 30%, 60% and 100% fish meal, and effects on feed intake, weight gain and feed gain ratio were determined in a 56-day growth trial. Some groups were then grown beyond 56 days, until all reached an average weight of 50 g. A comparison of body composition at 50 g showed no significant differences in protein and ash content among all fish, while lipid and energy contents were different. The 100% RPC and 60% and 100% SPC replacement diets had lower body lipid and energy contents compared with those of the control diet. Feed intake and weight gains were inversely related to inclusion levels of plant proteins. Feed intake dropped to 52–72% of that of the control treatment and weight gain to 46–61%. Energy retention followed this same trend, decreasing from ERV values of 53 to 44 with an increase in dietary plant protein content. With the exception of 100% SPC substitution (PPV = 35), protein retention among treatments was similar (PPV = 37–39). These results suggest that both SPC and RPC may be promising protein sources for inclusion in seabream diets. The relative palatability of these plant proteins could be a limiting factor in their use.

Substitution of Plant Proteins or Meat and Bone Meal for Fish Meal in Diets of Nile Tilapia

Abstract Five experimental diets containing plant proteins and synthetic amino acids with and without fish meal or meat and bone meal were fed to Nile tilapia Oreochromis niloticus averaging 13 g for 84 d in aquaria. Each experimental diet contained 20% corn gluten meal, 34–40% high-lysine corn, 29–36% soy grits, 0 or 6% fish meal or meat and bone meal, and supplemented with synthetic lysine, tryptophan, and threonine. There were no significant differences (P > 0.05) in weight gain, feed conversion ratio, and protein efficiency ratio for Nile tilapia fed the all plant protein diet, the fish meal diets with two levels of fat, the meat-and-bone-meal diets with two levels of fat, and the commercial diet containing fish meal and meat and bone meal. Thus, substitution of plant proteins or meat and bone meal for fish meal in Nile tilapia diets did not affect growth response.

Use of nonlinear regression to evaluate the effects of phytase enzyme treatment of plant protein diets for rainbow trout ( Oncorhynchus mykiss)

The effects of dietary phytase enzyme treatment and increasing ration on growth, body composition, nutrient digestibility and retention and phosphorus release in effluent water were studied in rainbow trout ( Oncorhynchus mykiss). Rainbow trout (initial weight: 115.3±0.49, mean±S.D.) were randomly distributed among 24 tanks and fed two experimental diets (A and B) each at six feeding levels (0.5, 1.0, 1.5, 2.0, 2.5 b.w. and satiation for 49 days). The two diets contained 33% soybean meal and differed only by the addition of 1000 U phytase/kg to diet B. The apparent digestibility coefficients for dry matter, crude protein, lipid, N-free extract, gross energy and ash of the two diets did not differ statistically. The phytase in diet B increased apparent digestibility of phosphorus (P) from 58.6 to 68.1% ( P<0.01). Daily gain and FCR improved in fish fed diet B with feeding levels greater than 1.5 and the best fit of the data was by using logistic and quadratic regression, respectively. Body protein, ash and P content decreased in fish fed diet A and with increasing ration up to 2.0% feeding rate and then reached a plateau. In contrast, body energy concentrations increased up to the same feed ration level and than levelled off. A significant difference ( P<0.05) between diets was only observed for body ash content. Body protein, ash and P retention decreased while energy retention increased in fish fed diet A and with increasing feeding levels. Best fit was obtained by using an exponential model for body protein ( P<0.05) and a quadratic model for the other body composition variables. Phosphorus released into the environment was higher for fish fed diet A ( P<0.05) and increased with increasing feeding level. A semilogarithmic model showed the best fit of the experimental data for P release.

Cowpea (Vigna unguiculata) protein concentrate as replacement for fish meal in diets for tilapia (Oreochromis niloticus) fry

This study provides information on the dietary efficiency of protein concentrate from cowpea seed, as an ingredient for practical diets of tilapia fry. Five experimental diets were prepared in which animal protein (fish meal) was replaced by increasing amounts of plant protein, and fed to tilapia during a nine-week period to assess the effect on growth, survival and feed efficiency. The highest growth rate and feed utilization was observed with 20–30% replacement of fish meal with cowpea protein concentrate, while the protein efficiency was best at 40% inclusion level. No mortalities related to the dietary plant protein were recorded. It is concluded that cowpea seed protein concentrate is a potential ingredient for use in feeding tilapia fry, and its use is recommended at the inclusion levels described in this paper.

Effect of feeding muscovy ducklings different protein sources: Performance, θ‐3 fatty acid contents, and acceptability of their tissues

AbstractOne hundred Muscovy ducklings, 5‐wk‐old, from each gender were assigned to five dietary treatments. Each treatment of each sex contained two replicates of 10 ducklings each. Ducks were fed, from 4–9 wk of age, five isonitrogenous diets that differed in protein source, i.e., commercial protein concentrate (CPC), soybean meal, meat meal (MM), herring fish meal (HFM), and mixed herring fish and meat meals (HFM + MM). At the end of the experiment, four ducks per treatment were slaughtered for carcass evaluation and the fatty acid profiles of their meat, adipose tissue, and plasma. Final body weight of both sexes showed no difference among protein sources, although males fed CPC or MM diets had the largest weight gain. No differences in feed consumption and conversion between sexes were shown, although differences in θ‐3 fatty acid consumption due to protein source were significant. Feeding fish meal reduced the sensory acceptance of meat, whereas the plant protein diet improved it. Total lipid and cholesterol contents of the meat of males showed no differences between protein sources. Correlation between θ‐3 fatty acid consumption and plasma cholesterol was negative (r=0.91; P=0.03). Moreover, correlation between plasma cholesterol and plasma lipid was positive (r=0.97; P=0.01). Feeding fish meal enriched total unsaturated fatty acid of adipose tissues, θ‐3 fatty acid of adipose and meat tissues, and total unsaturated fatty acid of thigh meat. Total unsaturated fatty acid and θ‐3 fatty acid of blood plasma from females were also enriched by feeding fish meal‐containing diets.

Vitamin B-6 requirement and status assessment: young women fed a depletion diet followed by a plant- or animal-protein diet with graded amounts of vitamin B-6.

The vitamin B-6 requirement of young women consuming a high-protein diet (1.55 g/kg body wt) and the effect of protein quality on this requirement was studied. In addition, the response of clinical, functional, and biochemical measures of vitamin B-6 nutriture to short-term depletion and step-wise repletion of vitamin B-6 were evaluated. Eight healthy young women resided in a metabolic unit and were fed a formula depletion diet (< 0.05 mg vitamin B-6/d) for 11-28 d followed by either an animal-protein (AP) or plant-protein (PP) diet with successively increasing vitamin B-6 intakes (0.5, 1.0, 1.5, and 2.0 mg/d) for periods of 14-21 d. Animal proteins were primarily from dairy and poultry sources and plant proteins were primarily from legumes. Vitamin B-6 status measures were assessed at weekly intervals. Results showed that a PP diet does not elevate the vitamin B-6 requirement over that required for an AP diet given the high amount of dietary protein used in this study. It was also found that 0.015 mg vitamin B-6/g protein intake normalized most biochemical indexes of vitamin B-6 status (including those indicative of functional status), and that 0.020 mg/g protein normalized all biochemical measures except total urinary vitamin B-6. Adding a margin of safety to either the 0.015 or 0.020 mg/g protein intake would raise the vitamin B-6 requirement for young women above the currently recommended dietary allowance of 0.016 mg/g protein.

Vitamin B-6 requirement and status assessment: young women fed a depletion diet followed by a plant- or animal-protein diet with graded amounts of vitamin B-6

The vitamin B-6 requirement of young women consuming a high-protein diet (1.55 g/kg body wt) and the effect of protein quality on this requirement was studied. In addition, the response of clinical, functional, and biochemical measures of vitamin B-6 nutriture to short-term depletion and step-wise repletion of vitamin B-6 were evaluated. Eight healthy young women resided in a metabolic unit and were fed a formula depletion diet (< 0.05 mg vitamin B-6/d) for 11-28 d followed by either an animal-protein (AP) or plant-protein (PP) diet with successively increasing vitamin B-6 intakes (0.5, 1.0, 1.5, and 2.0 mg/d) for periods of 14-21 d. Animal proteins were primarily from dairy and poultry sources and plant proteins were primarily from legumes. Vitamin B-6 status measures were assessed at weekly intervals. Results showed that a PP diet does not elevate the vitamin B-6 requirement over that required for an AP diet given the high amount of dietary protein used in this study. It was also found that 0.015 mg vitamin B-6/g protein intake normalized most biochemical indexes of vitamin B-6 status (including those indicative of functional status), and that 0.020 mg/g protein normalized all biochemical measures except total urinary vitamin B-6. Adding a margin of safety to either the 0.015 or 0.020 mg/g protein intake would raise the vitamin B-6 requirement for young women above the currently recommended dietary allowance of 0.016 mg/g protein.