Relationship between Plasma Vitamin A and Liver Vitamin A in Calves Fed a Vitamin A Depletion Ration and Calves Fed Minimum Levels of Vitamin A or Carotene

Urinary and fecal excretion of radioactive metabolites has been followed for 8 days (12 days in one group) in groups of rats having different initial body stores of vitamin A and given a single oral dose of 11,12-3H-retinyl acetate in oil. During the collections animals were fed a vitamin A deficient diet except for one group which was given laboratory chow throughout. At the end of the collection period animals were killed for determination of liver, kidney, and plasma vitamin A and radioactivity. Specific activities were similar in the three tissues; total liver vitamin A contents ranged from undetectable to 7700 μg. Excretion of fecal and urinary radioactivity was high initially but fell to apparently stable levels by day 8. When the combined urinary and fecal excretion was expressed in terms of the liver vitamin A equivalent (ELV), there was a gradual increase in excretion rate with the logarithm of liver vitamin A up to 150–300 μg/g liver; thereafter the rate of excretion increased more rapidly with liver stores to the highest level studied, 500–550 μg/g. In the initial phase the ELV values were 4–10 μg/day, rising to 22–24 μg/day in the second phase. These studies suggest that (a) a portion of newly absorbed vitamin A is metabolized before mixing with general body pools and probably without greatly altering the metabolism of endogenous vitamin A, (b) after equilibration of body pools, urinary excretion of radioactivity should be a useful index in experimental studies of factors affecting vitamin A metabolism, and (c) chemical determination of urinary metabolites of vitamin A is a potential index of vitamin A nutritional status.

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The relationship between concentrations of plasma and hepatic vitamin A in steers intensively finished on high-grain rations low in carotene

Australian Journal of Experimental Agriculture ◽

10.1071/ea9670213 ◽

1967 ◽

Vol 7 (26) ◽

pp. 213

Author(s):

RJW Gartner ◽

JG Morris ◽

GR Clark

Keyword(s):

Body Weight ◽

Vitamin A ◽

Correlation Coefficient ◽

Standard Error ◽

Regression Coefficients ◽

Plasma Vitamin ◽

The Relationship ◽

Large Standard Error ◽

Liver Vitamin

Data on plasma and liver vitamin A concentrations were obtained from 84 Hereford steers approximately two years of age and approximately 900 lb in body-weight. The animals were sampled from two experiments : 57 received high-grain rations low in carotene for 150 � 15 days, 27 received similar rations for 154 � 6 days. Plasma vitamin A levels in 18 animals were below 20 �g/100 ml, and these values were associated with hepatic levels of less than 10 �g/g. The regression of plasma vitamin A on the logarithm of liver vitamin A was significant (P<0.01) and the regression coefficients were not significantly different between experiments. The equation was y = -30.506 + 19.705 log x. This equation has only limited value for prediction over the whole range tested due to the large standard error (9.24) and the limited magnitude of the correlation coefficient (0.80).

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Plasma Vitamin A Homeostasis: The Relative Dose Response As A Measure Of Liver Vitamin A Reserves

Nutrition Reviews ◽

10.1111/j.1753-4887.1979.tb06643.x ◽

2009 ◽

Vol 37 (11) ◽

pp. 361-364

Keyword(s):

Vitamin A ◽

Dose Response ◽

Plasma Vitamin ◽

Liver Vitamin

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Plasma Vitamin A, D and E and Liver Vitamin A in Growing Holstein Friesian Bulls

Journal of the Japan Veterinary Medical Association ◽

10.12935/jvma1951.48.307 ◽

1995 ◽

Vol 48 (5) ◽

pp. 307-311

Author(s):

Jun SATO ◽

Reeko SATO ◽

Hisashi TAKAKI ◽

Taichi GOTO ◽

Yoshihisa NAITO

Keyword(s):

Vitamin A ◽

Plasma Vitamin ◽

Holstein Friesian ◽

Liver Vitamin

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Effect of dietary protein level and thyroxine on vitamin A depletion from liver in chicks

British Journal Of Nutrition ◽

10.1079/bjn19660006 ◽

1966 ◽

Vol 20 (1) ◽

pp. 41-53 ◽

Cited By ~ 12

Author(s):

I. Nir ◽

I. Ascarelli

Keyword(s):

Vitamin A ◽

Plasma Protein ◽

Dietary Protein ◽

Protein Level ◽

Electrophoretic Pattern ◽

Protein Malnutrition ◽

Plasma Vitamin ◽

Dietary Protein Level ◽

Plasma Protein Level ◽

Liver Vitamin

1. The effect of dietary protein level and supplementation with thyroxine and thiouracil on depletion of liver stores of vitamin A, on the percentage of liver vitamin A in the alcohol form and on the plasma level of vitamin A and protein has been studied in chicks. In an experiment with cockerels the relation was investigated between the vitamin A level of plasma and the electrophoretic pattern of its proteins.2. Liver vitamin A depletion was considerably reduced by lowering the dietary protein level.3. Protein malnutrition lowered the percentage of vitamin A found in the liver in the alcohol form.4. Depletion of vitamin A from the liver was related to the percentage of vitamin A in the alcohol form.5. Thyroxine increased both vitamin A depletion from the liver and the percentage of vitamin A in the alcohol form, whereas thiouracil had the opposite effect.6. Plasma vitamin A, and plasma protein contents were significantly lowered in cockerels receiving a 5% protein diet. The drop in plasma protein level was essentially caused by a reduction of the albumin fraction. No significant change in the levels of globulins was observed even after a 4-week period of protein malnutrition.7. When the dietary protein level was restored to normal both the albumin and vitamin A levels in plasma increased.

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The Relationship between the Blood Plasma Vitamin A Levels of Sows and of their Suckling Pigs

Journal of Animal Science ◽

10.2527/jas1956.152400x ◽

1956 ◽

Vol 15 (2) ◽

pp. 400-406

Author(s):

I. R. Sibbald ◽

J. P. Bowland ◽

R. T. Berg

Keyword(s):

Vitamin A ◽

Blood Plasma ◽

Plasma Vitamin ◽

The Relationship

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The Composition of Liver Vitamin A Ester and the Synthesis of Vitamin A Ester by Liver Microsomes

Journal of Biological Chemistry ◽

10.1016/s0021-9258(18)91136-1 ◽

1964 ◽

Vol 239 (12) ◽

pp. 4077-4080

Author(s):

Sidney Futterman ◽

J. Stevens Andrews

Keyword(s):

Vitamin A ◽

Liver Microsomes ◽

Liver Vitamin

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CFTR Modulator Therapy with Lumacaftor/Ivacaftor Alters Plasma Concentrations of Lipid-Soluble Vitamins A and E in Patients with Cystic Fibrosis

Antioxidants ◽

10.3390/antiox10030483 ◽

2021 ◽

Vol 10 (3) ◽

pp. 483

Author(s):

Olaf Sommerburg ◽

Susanne Hämmerling ◽

S. Philipp Schneider ◽

Jürgen Okun ◽

Claus-Dieter Langhans ◽

...

Keyword(s):

Cystic Fibrosis ◽

Vitamin E ◽

Vitamin A ◽

Clinical Chemistry ◽

Pancreatic Insufficiency ◽

Plasma Concentrations ◽

Plasma Vitamin ◽

Hypervitaminosis A ◽

Cholesterol Ratio ◽

Fat Soluble Vitamins

Rationale: Cystic fibrosis (CF), caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, leads to impaired pancreatic function and therefore reduced intestinal absorption of lipids and fat-soluble vitamins especially in patients with CF developing pancreatic insufficiency (PI). Previous studies showed that CFTR modulator therapy with lumacaftor-ivacaftor (LUM/IVA) in Phe508del-homozygous patients with CF results in improvement of pulmonary disease and thriving. However, the effects of LUM/IVA on plasma concentration of the lipid soluble vitamins A and E remain unknown. Objectives: To investigate the course of plasma vitamin A and E in patients with CF under LUM/IVA therapy. Methods: Data from annual follow-up examinations of patients with CF were obtained to assess clinical outcomes including pulmonary function status, body mass index (BMI), and clinical chemistry as well as fat-soluble vitamins in Phe508del-homozygous CF patients before initiation and during LUM/IVA therapy. Results: Patients with CF receiving LUM/IVA improved substantially, including improvement in pulmonary inflammation, associated with a decrease in blood immunoglobulin G (IgG) from 9.4 to 8.2 g/L after two years (p < 0.001). During the same time, plasma vitamin A increased significantly from 1.2 to 1.6 µmol/L (p < 0.05), however, levels above the upper limit of normal were not detected in any of the patients. In contrast, plasma vitamin E as vitamin E/cholesterol ratio decreased moderately over the same time from 6.2 to 5.5 µmol/L (p < 0.01). Conclusions: CFTR modulator therapy with LUM/IVA alters concentrations of vitamins A and vitamin E in plasma. The increase of vitamin A must be monitored critically to avoid hypervitaminosis A in patients with CF.

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