-
[show abstract]
[hide abstract]
ABSTRACT: Zeaxanthin is a predominant xanthophyll in human eyes and may reduce the risk of cataracts and age-related macular degeneration. Spirulina is an algal food that contains a high concentration of zeaxanthin. In order to determine the zeaxanthin bioavailability of spirulina for dietary supplementation in humans, spirulina was grown in nutrient solution with ²H₂O for carotenoid labelling. Single servings of ²H-labelled spirulina (4.0-5.0 g) containing 2.6-3.7 mg zeaxanthin were consumed by fourteen healthy male volunteers (four Americans and ten Chinese) with 12 g dietary fat. Blood samples were collected over a 45 d period. The serum concentrations of total zeaxanthin were measured using HPLC, and the enrichment of labelled zeaxanthin was determined using LC-atmospheric pressure chemical ionisation-MS (LC-APCI-MS). The results showed that intrinsically labelled spirulina zeaxanthin in the circulation was detected at levels as low as 10 % of the total zeaxanthin for up to 45 d after intake of the algae. A single dose of spirulina can increase mean serum zeaxanthin concentration in humans from 0.06 to 0.15 μmol/l, as shown in our study involving American and Chinese volunteers. The average 15 d area under the serum zeaxanthin response curve to the single dose of spirulina was 293 nmol × d/μmol (range 254-335) in American subjects, and 197 nmol × d/μmol (range 154-285) in Chinese subjects. It is concluded that the relative bioavailability of spirulina zeaxanthin can be studied with high sensitivity and specificity using ²H labelling and LC-APCI-MS methodology. Spirulina can serve as a rich source of dietary zeaxanthin in humans.
The British journal of nutrition 02/2012; 108(4):611-9. · 3.45 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The study was carried out to analyze serum carotenoids concentration of some Chinese adults by HPLC.
One hundred and eighty four 30 - 60 year-old adults (84 males and 100 females) from three different communities were recruited in the investigation. The fast blood samples were collected and separated into serum in summer, autumn, winter and spring of the year, respectively. The serum were extracted with organic solvents and analyzed with a HP1100 HPLC for the concentration of beta-carotene, alpha-carotene, beta-cryptoxanthin, lycopene, and lutein/zeaxanthin.
The average serum concentration of carotenoids of investigated population in summer, autumn, winter and spring were as followed (inmicromol/L), respectively: beta-carotene, 0.72 +/- 0.20, 0.71 +/- 0.18, 0.70 +/- 0.19 and 0.63 +/- 0.20; alpha-carotene, 0.037 +/- 0.018, 0.039 +/- 0.015, 0.038 +/- 0.017 and 0.030 +/- 0.019; beta-cryptoxanthin, 0.11 +/- 0.03, 0.14 +/- 0.03, 0.13 +/- 0.04 and 0.10 +/- 0.03; lutein + zeaxanthin, 0.61 +/- 0.16, 0.45 +/- 0.09, 0.46 +/- 0.12 and 0.47 +/- 0.14; lycopene, 0.43 +/- 0.26, 0.11 +/- 0.06, 0.07 +/- 0. 04 and 0.07 +/- 0.03. The average serum beta-carotene concentration of total-population was lowest in spring, but the descent did not occurred from urban sub-population. There were significant seasonal changes in average serum concentrations of alpha-carotene, beta-cryptoxanthin, lutein + zeaxanthin, and lycopene from total population. Further more, there was significant difference of serum concentration of every carotenoid between three sub-populations in every season.
The data of serum carotenoid concentration in total 713 blood samples from some Chinese adults were reported here, which would be helpful to understanding the population distribution of carotenoid concentration in China.
Wei sheng yan jiu = Journal of hygiene research 09/2011; 40(5):591-5.
-
Jie Wang,
Yin Wang, Zhixu Wang,
Lei Li,
Jian Qin,
Weiqi Lai,
Ying Fu,
Paolo M Suter,
Robert M Russell,
Michael A Grusak,
Guangwen Tang,
Shian Yin
[show abstract]
[hide abstract]
ABSTRACT: Spirulina is a high-protein food supplement that contains carotenoids.
The objective of the study was to determine the vitamin A equivalence of spirulina beta-carotene in humans.
Spirulina was grown in a 23 atom% (2)H(2)O cultural solution. Spirulina beta-carotene showed the greatest enrichment as [(2)H(10)]trans beta-carotene. Ten healthy Chinese men with a mean (+/-SD) serum retinol concentration of 1.7 +/- 0.3 micromol/L and a body mass index (in kg/m(2)) of 23 +/- 3 consumed 5.8 micromol [(13)C(10)]retinyl acetate in oil as a reference dose with a breakfast containing 13 g fat. One week later, each subject consumed 7.9 mumol trans beta-carotene in spirulina with a breakfast containing 22 g fat. All subjects followed diets low in carotenoid and vitamin A. Forty blood samples were collected from each subject over a span of 56 d. Concentrations and enrichments of retinol and beta-carotene in serum samples were determined by using HPLC and a mass spectrometer.
Compared with the serum response to [(13)C(10)]retinyl acetate dose, the mean conversion factor of spirulina beta-carotene to retinol was 4.5 +/- 1.6 (range: 2.3-6.9) by weight. It was estimated that 80% of the conversion occurred within the first 24 h after spirulina administration.
In a group of well-nourished, normal-weight Chinese men following low-vitamin A diets, 4.5 mg spirulina beta-carotene consumed with 22 g fat has the same vitamin A activity as does 1 mg retinyl acetate.
American Journal of Clinical Nutrition 07/2008; 87(6):1730-7. · 6.67 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Vitamin A (VA) kinetics, storage, and disposal rate were determined in well-nourished Chinese and U.S. adults using model-based compartmental analysis. [(2)H(8)]Retinyl acetate (8.9 micromol) was orally administered to U.S. (n = 12; 59 +/- 9 y; mean +/- SD) and Chinese adults (n = 14; 54 +/- 4 y) and serum tracer and VA concentrations were measured from 3 h to 56 d. Using the Windows version of the Simulation, Analysis and Modeling software, we determined that the average time from dosing until appearance of labeled retinol in serum was greater in U.S. subjects (40.6 +/- 8.47 h) than in Chinese subjects (32.2 +/- 5.84 h; P < 0.01). Model-predicted total traced mass (898 +/- 637 vs. 237 +/- 109 micromol), disposal rate (14.7 +/- 5.87 vs. 5.58 +/- 2.04 micromol/d), and system residence time (58.9 +/- 28.7 vs. 42.9 +/- 14.6 d) were greater in U.S. than in Chinese subjects (P < 0.05). The model-predicted VA mass and VA mass estimated by deuterated retinol dilution at 3 and 24 d did not differ. VA disposal rate was positively correlated with VA traced mass in Chinese (R(2) = 0.556), U.S. (R(2) = 0.579), and all subjects (R(2) = 0.808). Additionally, VA disposal rate was significantly correlated with serum retinol pool size (R(2) = 0.227) and retinol concentration (R(2) = 0.330) in all subjects. Our results support the hypothesis that VA stores are the principle determinant of VA disposal rate in healthy, well-nourished adults.
Journal of Nutrition 05/2008; 138(5):971-7. · 3.92 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To determine the vitamin A equivalence of spinach beta-carotene (beta-C) in human body.
Spinach grown in 25 atom% 2H2O cultural solution was intrinsically labeled by deuterium. The highest enrichment of spinach trans-beta-C isotopomers was at the molecular mass of 547 (2H10 trans-beta-C). Ten healthy Chinese male adults (43-56y) were given a dose of 5.8 micromol 13C10 retinyl acetate as vitamin A reference dose. One week later, each subject was given 100g of steamed spinach (containing 7.0 micromol beta-C). Forty blood samples were collected over 56 days from each subject. A HPLC method was used to detect the concentrations of retinol and beta-C in serum, and a GC-MS method was used to detect the enrichment of the labeled retinol. Kinetic curves of the labeled retinol from the reference dose and the spinach beta-C were compared to determine the vitamin A equivalence of spinach beta-C.
The results showed that 1 nmol spinach beta-C provided (0.25 +/- 0.10) nmol retinol. The mean conversion factor of spinach beta-C to vitamin A was (9.0 +/- 4.5) : 1 by weight.
The bioconversion of spinach beta-C to vitamin A was determined in 10 Chinese male adults by stable isotope tracer and reference techniques, and the mean conversion factor was 9.0 to 1 on a weight basis.
Wei sheng yan jiu = Journal of hygiene research 08/2007; 36(4):449-53.
-
[show abstract]
[hide abstract]
ABSTRACT: The present study was carried out to determine the conversion factor of synthetic (2)H-labelled beta-carotene to vitamin A in Chinese adults by using a stable-isotope dilution technique. Fifteen healthy volunteers aged 50-60 years were recruited for a 55 d experiment. The volunteers (nine males and six females) were each given a physiological dose of [(2)H8]beta-carotene (6 mg) in oil on the first day of the experiment, and a reference dose of [(2)H8]retinyl acetate (3 mg) in oil was given on the fourth day. Serum samples were collected at 0, 3, 5, 7, 9, 11, and 13 h on the first and the fourth days of the study, daily for 10 d, and then weekly from days 14 to 56. beta-Carotene and retinol were extracted from serum and isolated by HPLC, and their enrichments were respectively determined by using GC-electron capture negative chemical ionisation-MS and LC-atmospheric pressure chemical ionisation interface-MS. Four of the subjects exhibited beta-carotene to vitamin A conversion factors of >29.0:1 on a molar basis and were termed 'poor converters'. In the eleven normal converters (seven males and four females), the calculated conversion factors of beta-carotene to retinol ranged from 2.0:1 to 12.2:1 with an average of 4.8 (sd 2.8):1 on a molar basis, and from 3.8:1 to 22.8:1 with an average of 9.1 (sd 5.3):1 on a weight basis. The 52 d post-intestinal absorption conversion was estimated to be about 30 % of the total converted retinol.
British Journal Of Nutrition 01/2004; 91(1):121-31. · 3.01 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: beta-carotene (beta-C) is a major and safe vitamin A source for a vast population in China. But there is little understanding on beta-C-vitamin A equivalence in Chinese population. This study was designed to evaluate intestinal and whole-body conversion of beta-C to vitamin A in some Chinese adults by using a stable isotope dilution technique.
Fifteen healthy adult farmer volunteers (9 males and 6 females) aged 50-60 years from a few villages of China's eastern Shandong Province were recruited in a 55-days experiment. A Physiological dose of 2H8 beta-C (11011 nmole or 6 mg) in oil was given with a liquid diet (25% energy from fat) to the volunteers in the first day of the study. Three days after the 2H8 beta-C dose, the volunteers each took a reference dose of 2H8 RAC (8,915 nmole or 3 mg) in oil with the same liquid diet. Serum samples were collected at 0, 3, 5, 7, 9, 11, 13 hours of the first and the fourth days of study, and fasting serum samples were also collected daily in first 10 days and then weekly at 14th, 21st, 28th, 35th, 42nd, 49th, and 56th day after a 12-hour overnight fast, beta-C and retinol were extracted from serum and isolated by high performance liquid chromatography. The serum retinol and beta-C enrichments were respectively determined by using a gas chromatography/electron capture negative chemical ionization mass spectrometry (GC/ECNCI-MS) and liquid chromatograph/mass spectrometry with an atmospheric pressure chemical ionization interface (LC/APCI-MS).
All the subjects responded well to the 2H8 retinyl acetate reference dose. However, the responses to the 2H8 beta-C dose were unexpectedly Poor in 4 of the 15 subjects. The repeated GC-MS analysis on the backup serum samples confirmed that these 4 subjects responded less efficiently to ingested 2H8 beta-C dose. These 4 subjects referred as to poor converters will be re-examined to confirm the observation. Therefore, the data of beta-C metabolism of the 4 poor converters were not analyzed together with that of the 11 normal converters. In the normal converters (7 males and 4 females), the calculated conversion factor of beta-C to retinol in1, 6, 13, 20, 27, 34, 41, and 52 days are 7.1 +/- 3.4, 5.6 +/- 2.7, 5.4 +/- 2.9, 5.1 +/- 2.8, 5.0 +/- 3.0, 5.0 +/- 2.9, 4.9 +/- 2.9, 4.8 +/- 2.8 to 1 on a molar basis respectively, and the corresponding post intestinal absorption conversion is estimated as (19.7 +/- 17.8)%, (22.7 +/- 20.5)%, (26.3 +/- 21.2)%, (27.8 +/- 22.7)%, (28.6 +/- 22.7)%, (29.5 +/- 22.8)% and (30.1 +/- 22.1)% of the total converted retinol.
The different time conversion of beta-C to vitamin A in the tested Chinese adults had been quantitatively determined by using a stable isotope reference method, and the long term as 52 days conversion factor value was 9.1 to 1 on a weight basis, and about 30% of total converted retinol came from absorbed intact beta-C.
Wei sheng yan jiu = Journal of hygiene research 06/2003; 32(3):215-21.
-
[show abstract]
[hide abstract]
ABSTRACT: Anemia morbidity in the population of adolescent and post-adolescent high school student has been paid little attention. Iron deficiency anemia is one of common maladies of micronutrient depletions, which has been proven to be damaging to cognition and intelligence performance. To probe into relationship between possible micronutrient deficiencies among post-adolescent schoolgirls and their poor intelligence performance comparing with same aged boys, this investigation was carried out.
Blood hemoglobin levels of 2624 senior high school student, including 1050 females and 1754 males with average age of 18.89 +/- 1.30 years, were determined at the time when they took part in physical examination for the National University Entrance Test.
Anemic prevalence among female high-school graduates was 11.3%, much higher than 1.5% of males (P < 0.001).
The high anemic morbidity in post-adolescent high schoolgirls exists, and it may be turned up to be one of causes of dropping behind in school test performance to them.
Wei sheng yan jiu = Journal of hygiene research 03/2003; 32(2):144-6.
