Effects of Seasonal Vitamin D3 Supplementation on Strength, Power, and Body Composition in College Swimmers

2020 ◽  
Vol 30 (2) ◽  
pp. 165-173 ◽  
Author(s):  
Michelle S. Rockwell ◽  
Madlyn I. Frisard ◽  
Janet W. Rankin ◽  
Jennifer S. Zabinsky ◽  
Ryan P. Mcmillan ◽  
...  
Keyword(s):  
Vitamin D ◽  
Body Composition ◽  
Vertical Jump ◽  
Free Testosterone ◽  
Fat Free Mass ◽  
Sex Hormone Binding Globulin ◽  
Total Testosterone ◽  
Hormone Binding ◽  
Anabolic Hormones ◽  
Fall Season

The purpose of this study was to evaluate the impact of fall season vitamin D3 supplementation on strength/power, body composition, and anabolic hormones in swimmers with optimal vitamin D status at summer’s end. Male and female National Collegiate Athletic Association Division I swimmers (N = 19) with optimal 25-hydroxyvitamin D [25(OH)D] randomly received 5,000 IU of vitamin D3 (VITD) or placebo (PLA) daily for 12 weeks while participating in swimming and strength and conditioning training (August–November). Before and after the intervention, the participants underwent blood sampling for analysis of serum 25(OH)D, parathyroid hormone, total testosterone, free testosterone, sex hormone-binding globulin, and insulin-like growth factor 1, dual-energy X-ray absorptiometry, and strength/power testing (bench press, squat, dead lift, standing broad jump, vertical jump, and dips and pull-ups). Sex was used as a covariate for analyses. The 25(OH)D was decreased by 44% in PLA (p < .05) and increased by 8% in VITD over the 12 weeks. Fat-free mass increased in VITD (56.4–59.1 kg; p < .05), but not PLA (59.4–59.7 kg; p < .01). Significant Group × Time interaction effects were observed for dead lift (F = 21.577, p < .01) and vertical jump (F = 11.219, p < .01), but no other strength/power tests. Total testosterone decreased similarly in both groups, but free testosterone decreased and sex hormone-binding globulin increased only in PLA (p < .01). There were no group differences or changes in insulin-like growth factor 1 with the intervention. The findings suggest that vitamin D supplementation is an efficacious strategy to maintain 25(OH)D during the fall season training and to enhance some aspects of strength/power and fat-free mass in swimmers. Further research on the relationship between vitamin D and anabolic hormones is needed.

scholarly journals Testosterone, sex hormone-binding globulin, calculated free testosterone, and oestradiol in male vegans and omnivores

1990 ◽  
Vol 64 (1) ◽  
pp. 111-119 ◽  
Author(s):  
Timothy J. A. Key ◽  
Liane Roe ◽  
Margaret Thorogood ◽  
John W. Moore ◽  
Graham M. G. Clark ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Polyunsaturated Fatty Acids ◽  
Saturated Fatty Acids ◽  
Free Testosterone ◽  
Sex Hormone ◽  
Sex Hormone Binding Globulin ◽  
Vegan Diet ◽  
Total Testosterone ◽  
Hormone Binding ◽  
Diet Records

Total testosterone (T), total oestradiol (E2) and sex hormone-binding globulin (SHBG) concentrations were measured in plasma samples from fifty-one male vegans and fifty-seven omnivores of similar age. Free T concentration was estimated by calculation, in comparison with the omnivores, the vegans had 7% higher total T (P = 0.250), 23% higher SHBG (P = 0.001), 3% lower free T (P = 0.580), and 11% higher E2 (P = 0.194). In a subset of eighteen vegans and twenty-two omnivores for whom 4 d diet records were available, there were statistically significant correlations between T and polyunsaturated fatty acids (r 0.37), SHBG and fat (r 0.43 for total fat, 0.46 for saturated fatty acids and 0.33 for polyunsaturated fatty acids), and SHBG and alcohol (r–0.39). It is concluded that a vegan diet causes a substantial increase in SHBG but has little effect on total or free T or on E2.

Peripheral hormone levels in healthy subjects during controlled fasting

1986 ◽  
Vol 113 (3) ◽  
pp. 457-462 ◽  
Author(s):  
Ragnar Tegelman ◽  
Pia Lindeskog ◽  
Kjell Carlström ◽  
Åke Pousette ◽  
Rolf Blomstrand
Keyword(s):  
Protein Binding ◽  
Testosterone Level ◽  
Healthy Subjects ◽  
Free Testosterone ◽  
Sex Hormone ◽  
Sex Hormone Binding Globulin ◽  
Total Testosterone ◽  
Metabolic Clearance ◽  
Dehydroepiandrosterone Sulphate ◽  
Hormone Binding

Abstract. The effect of one week of controlled fasting (3 1 of fluid containing 50 g of carbohydrate/day) upon the serum levels of hormones, sex hormone binding globulin, and albumin was studied in healthy subjects. Fasting caused decreased levels of prolactin and T3, no changes in the levels of TSH, FSH, LH, dehydroepiandrosterone, 4-androstene-3,17-dione, total oestrone, and total testosterone, and increased levels of cortisol, dehydroepiandrosterone sulphate and albumin. A significant positive correlation was found between albumin and dehydroepiandrosterone sulphate. Fasting rapidly increased the levels of sex hormone binding globulin and decreased the percentage of free testosterone and the calculated free testosterone level in both sexes. A decreased metabolic clearance of certain steroids (cortisol, dehydroepiandrosterone sulphate) owing to an increased protein binding may be one of the endocrine consequences of fasting. An increased protein binding of testosterone may be outweighed by a decreased gonadal production, thus resulting in an unchanged total testosterone level. The increased sex hormone binding globulin level could not be explained by changes in gonadal and thyroid hormones.

scholarly journals Salivary and Plasma Free Testosterone and Androstenedione Levels in Women Using Oral Contraceptives Containing Desogestrel or Levonorgestrel

1988 ◽  
Vol 25 (4) ◽  
pp. 354-359 ◽  
Author(s):  
L M J W Swinkels ◽  
P M M Meulenberg ◽  
H A Ross ◽  
Th J Benraad
Keyword(s):  
Oral Contraceptives ◽  
Plasma Concentrations ◽  
Free Testosterone ◽  
Sex Hormone ◽  
Sex Hormone Binding Globulin ◽  
Total Testosterone ◽  
Hormone Binding ◽  
Direct Assay

The effect of oral contraceptives (OC) containing a combination of ethinyloestradiol (EE2) and either desogestrel (Dg/EE2) or levonorgestrel (Lg/EE2) on plasma concentrations of sex hormone binding globulin (SHBG), total testosterone (T), free T, total androstenedione (A), free A and on salivary T and A concentrations have been studied. SHBG concentrations were higher in the Dg/EE2 group than in the Lg/EE2 group. Total T, measured by RIA with prior extraction and chromatography, is also higher in the Dg/EE2 group. Per cent free T was lower in the Dg/EE2 group. Plasma free T and free A concentrations were the same in both groups. However, free T and free A were significantly lower in the OC-groups than in controls. In contrast, by direct assay, no difference in total T was observed between the OC-groups. Since the per cent free T was lower in the Dg/EE2 group, it would be concluded that free T in the Dg/EE2 group is lower than in the Lg/EE2 group. Salivary free T and free A concentrations did not differ between control and OC-groups. There was good correlation between salivary and free hormone concentrations within each group. We conclude that the concentrations of androgens in saliva do not necessarily directly reflect their free concentrations in plasma.

scholarly journals Vitamin D and Gynecologic Outcomes: Insights from the EAGeR Trial

2018 ◽  
Author(s):  
Daniel Lee Kuhr
Keyword(s):  
Vitamin D ◽  
Menstrual Cycle ◽  
Cycle Length ◽  
Free Testosterone ◽  
Physical Symptoms ◽  
Sex Hormone Binding Globulin ◽  
Total Testosterone ◽  
Serum Samples ◽  
Menstrual Cycles ◽  
Menstrual Cycle Length

Context: Vitamin D is associated with a host of reproductive outcomes, but there is little research investigating these relationships in healthy, regularly cycling, premenopausal women.Objective: Our objective was to assess the relationship between vitamin D and hormonal biomarkers, sporadic anovulation, menstrual cycle length, and premenstrual syndrome and its symptoms. We hypothesize that vitamin D will be inversely associated with aberrations in reproductive and gynecologic function.Methods: This was a prospective cohort of 1191 participants attempting to conceive, aged 18-40, with 1-2 prior pregnancy losses, no history of infertility, and enrolled in the EAGeR trial. Patients answered questionnaires regarding demographic information and gynecologic histories and serum samples were collected pre-randomization. Patients collected and froze daily first-void urine samples for up to two menstrual cycles. Patients were followed for risk of anovulation for two menstrual cycles and followed all together for up to six menstrual cycles.Results: Vitamin D was associated with free androgen index and sex hormone binding globulin concentration, but not total testosterone, free testosterone, or dehydroepiandrosterone sulfate. Vitamin D was negatively associated with estrone-1-glucoronide in urine but not with pregnanediol glucuronide. Vitamin D was not associated with menstrual cycle length or its phase components and was not associated with risk of sporadic anovulation. Vitamin D was associated with breast tenderness/fullness and generalized aches and pains during the premenstrual week but not with other symptoms or overall risk of PMS.Conclusions: Vitamin D may play a role in a host of reproductive and endocrine outcomes, including the bioavailability of androgens, concentrations of estrogens, and physical symptoms of PMS.

Testosterone and its binding in hyperthyroid women before and under antithyroid drug therapy

1989 ◽  
Vol 121 (3) ◽  
pp. 443-446 ◽  
Author(s):  
Sylvain Loric ◽  
Françoise Duron ◽  
Jérôme Guéchot ◽  
Pierre Aubert ◽  
Jacqueline Giboudeau
Keyword(s):  
Drug Therapy ◽  
Antithyroid Drug ◽  
Free Testosterone ◽  
Sex Hormone ◽  
Sex Hormone Binding Globulin ◽  
Total Testosterone ◽  
Hormone Binding ◽  
Antithyroid Drug Therapy ◽  
Before And After ◽  
Hyperthyroid Patients

Abstract. The serum concentrations of the different forms of circulating testosterone, total testosterone, free testosterone and non-sex-hormone binding globulin bound testosterone (albumin bound + free fractions) which is considered as the biovailable hormone, were measured in 15 hyperthyroid women before and after anti-thyroid drug therapy and in 15 age-matched healthy women. Sex-hormone binding globulin and albumin were quantified. Total testosterone was significantly higher in hyperthyroid women before treatment, whereas free testosterone and non sex-hormone binding globulin bound testosterone were significantly decreased. After recovery, all the parameters returned to the normal range. In hyperthyroid patients, the variations in the different fractions of testosterone can be related to the rise of sex-hormone binding globulin. These variations could be explained by the displacement of the equilibrium defined by the binding equation.

Total testosterone, free-androgen index, calculated free testosterone, and free testosterone by analog RIA compared in hirsute women and in otherwise-normal women with altered binding of sex-hormone-binding globulin.

1987 ◽  
Vol 33 (8) ◽  
pp. 1372-1375 ◽  
Author(s):  
T J Wilke ◽  
D J Utley
Keyword(s):  
Free Testosterone ◽  
Sex Hormone ◽  
Sex Hormone Binding Globulin ◽  
Total Testosterone ◽  
Diagnostic Efficiency ◽  
Hormone Binding ◽  
Clinical Value ◽  
Free Androgen Index ◽  
Normal Limits ◽  
Normal Women

Abstract We compared the clinical value of information on free testosterone as measured with the Coat-A-Count (Diagnostic Products Corp.) radioimmunoassay kit involving a ligand analog with that of total testosterone, the free-androgen index, and free testosterone calculated from concentrations of testosterone, sex-hormone-binding globulin, and albumin, in hirsute women, pregnant women, oral-contraceptive users, women with thyroid disease, and epileptic women taking phenytoin. Total testosterone, the free-androgen index, calculated free testosterone, and free testosterone by RIA were increased in 41-68% of hirsute women. Values for free testosterone increased in the first and third trimesters of pregnancy but remained within normal limits in all non-hirsute groups. Total testosterone was increased in patients having increased sex-hormone-binding globulin, whereas the free-androgen index and, to a lesser extent, calculated free testosterone were significantly decreased. Free testosterone measured by analog RIA not only has greater diagnostic efficiency than total testosterone, it also is technically simpler to determine than the free-androgen index and calculated free testosterone.

scholarly journals Effects of SHBG rs1799941 Polymorphism on Free Testosterone Levels and Hypogonadism Risk in Young Non-Diabetic Obese Males

2019 ◽  
Vol 8 (8) ◽  
pp. 1136
Author(s):  
Daniel Castellano-Castillo ◽  
José Luis Royo ◽  
Ana Martínez-Escribano ◽  
Lidia Sánchez-Alcoholado ◽  
María Molina-Vega ◽  
...  
Keyword(s):  
Regression Models ◽  
Biological Function ◽  
Free Testosterone ◽  
Sex Hormone ◽  
Sex Hormone Binding Globulin ◽  
Total Testosterone ◽  
Hormone Binding ◽  
Testosterone Levels ◽  
Increased Risk ◽  
Lineal Regression

Introduction: Obesity has been associated with increased risk of presenting hypogonadism. Free testosterone (FT) is the fraction of testosterone that carries out the biological function of testosterone, and is determined from total testosterone (TT) and sex-hormone binding globulin (SHBG) levels. We aimed to study the SHBG polymorphism rs1799941 in a cohort of young non-diabetic obese males to unravel the possible implication of this polymorphism in obesity-related hypogonadism. Methodology: 212 young (<45 years) non-diabetic obese (BMI ≥ 30 kg/m2) males participated in this study. Subjects were classified according to TT and FT levels in: Eugonadal (n = 55, TT > 3.5 ng/mL and FT ≥ 70 pg/mL; EuG), normal FT hypogonadism (n = 40, TT < 3.5 and FT ≥ 70 pg/mL; normal FT HG) and hypogonadism (n = 117, TT < 3.5 ng/mL and TL < 70 pg/mL; HG). The SHBG rs1799941 polymorphism (GG/GA/AA) was analyzed using the Taqman Open Array (Applied biosystem). Results: The rs1799941 frequencies were different among the groups. Higher proportion of the allele (A) was found in HG, compared to EuG and normal FT HG. Among the genotypes, the rare homozygous (AA) were found in the normal FT HG group and higher levels of serum SHBG and lower of FT were observed. The presence of the allele A was related (according to lineal regression models) to an increased of SHBG levels ((GA) β = 3.28; (AA) β = 12.45) and a decreased of FT levels ((GA) β = −9.19; (AA) β = −18.52). The presence of the allele (A) increased the risk of presenting HG compared to normal FT HG (OR = 2.54). Conclusions: The rs1799941 of the SHBG gene can partially determine the presence of obesity-related hypogonadism in young non-diabetic males and whether these subjects have normal FT HG.

Relationship of high density lipoprotein cholesterol with total and free testosterone and sex hormone binding globulin

1983 ◽  
Vol 104 (2) ◽  
pp. 253-256 ◽  
Author(s):  
R. F. Heller ◽  
M. J. Wheeler ◽  
J. Micallef ◽  
N. E. Miller ◽  
B. Lewis
Keyword(s):  
Body Mass Index ◽  
High Density Lipoprotein ◽  
Body Mass ◽  
Density Lipoprotein ◽  
Hdl Cholesterol ◽  
Free Testosterone ◽  
Sex Hormone ◽  
Sex Hormone Binding Globulin ◽  
Total Testosterone ◽  
Hormone Binding

Abstract. A cross-sectional study was performed to see if the previously described association between high density lipoprotein (HDL) cholesterol and plasma total testosterone concentration reflected a relationship with free testosterone or with sex hormone binding globulin (SHBG). In 295 employed middle-aged men, measurements were made of total testosterone and SHBG in serum and of testosterone in saliva, and also of plasma total and HDL cholesterol, plasma triglycerides and other factors which might influence HDL cholesterol levels such as body mass index, alcohol and smoking habits and thyroid hormone levels. In a multiple regression analysis using the GLIM package programme total testosterone concentrations had a persistent positive association with HDL cholesterol (t = 3.5, P < 0.001) – this association was independent of SHBG (which had a negative association with HDL: t = −1.8, P <0.07. The association of HDL cholesterol with testosterone was independent of and stronger than the association of HDL cholesterol with body mass index, alcohol intake and cigarette smoking. Salivary testosterone (a measure of the circulating free hormone) also had a positive independent association with HDL cholesterol. The relationship between HDL cholesterol and testosterone thus appears to reflect an association with circulating hormone levels rather than with the hormone binding globulin.

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