Nonsignificant relation of seminal and serum vitamin D levels and semen parameters of males in Upper Egypt
Emad E Kamal1, Rania M Bakry2, Mary Y Danyail1, Aya Y Badran1
1 Department of Dermatology, Venereology and Andrology, Faculty of Medicine, Assiut University, Assiut, Egypt
2 Department of Clinical Pathology, South Cancer Institute, Assiut University, Assiut, Egypt
Correspondence Address:
Aya Y Badran
Lecturer of Dermatology, Venereology and Andrology, Department of Dermatology, Venereology and Andrology, Faculty of Medicine, Assiut University, Assiut, 71511
Egypt
Source of Support: None, Conflict of Interest: None
CheckDOI: 10.4103/ejdv.ejdv_56_20
Introduction Since the discovery of vitamin D (Vit. D) in 1922, a plethora of researches has been conducted on it describing its role in many physiological and pathological processes.
Aim This research targeted to assess both seminal and serum Vit. D levels in Egyptian males and to establish the relation between both serum and seminal Vit. D and the age, residence, education, marital and fertility states, and semen parameters of men in our community.
Patients and methods A prospective cross-sectional hospital-based study targeted men who attended the andrology clinic during the period from the beginning of May 2019 to the end of August 2019 with various complaints. All participants were subjected to conventional semen analysis using the WHO 2010 as a reference. Both serum and seminal Vit. D levels were assessed using enzyme-linked immunosorbent assay technique.
Results The study included 100 male participants. Their age ranged from 20.0 to 50.0 years, with a mean±SD of 34.97±8.37 years. Most of them were from rural areas of Upper Egypt (60 vs. 40% from urban areas). The participants were classified into groups according to semen analysis using the WHO 2010 criteria. Serum Vit. D deficiency, insufficiency, and normal levels were observed in 4, 25, and 71% of participants, respectively. Seminal Vit. D sufficiency and insufficiency were reported in 83 and 17%, respectively. Both serum and seminal Vit. D levels had nonsignificant correlations between their levels and all semen parameters.
Conclusion As most Egyptian men are subjected to sunny climate of our country, the prevalence of Vit. D deficiency is low in both serum and seminal fluid. The results of the current study did not support any evidence for the role of Vit. D in semen parameters or male fertility status.
Keywords: fertility, semen analysis, semen parameters, vitamin D
Vitamin D (Vit. D) has been discovered in 1922 as a novel therapy for treatment of rickets; since then, plenty of studies have clarified that Vit. D has many biological functions including skeletal and extraskeletal effects [1]. The main function of Vit. D is maintaining calcium, magnesium, as well as phosphate homeostasis through actions on different organs (intestines, bone, kidneys, and parathyroid glands) [2]. Moreover, it has a critical role in immune modulation and proliferation [3].
Vit. D are a set of secosteroids (steroids with broken ring), characterized by their fat solubility [4]. Vit. D3 (cholecalciferol) and Vit. D2 (ergocalciferol) are of utmost importance to humans. It has been found that Vit. D2 is present in mushrooms, whereas Vit. D3 is present in fish rich in oil such as salmon, mackerel, and herring. Both forms are synthetized by ultraviolet irradiation at a specific wave length of 290–320 nm [5]. Nevertheless, multiple factors affect the synthesis process such as the environmental nature, food, clothing, geographical location, and sun-avoidance methods such as sunscreens [6].
The 25 hydroxy-Vit. D [25(OH) Vit. D] is the major form of Vit. D in circulation, and it is considered the best indicator for Vit. D status. It is produced by hydroxylation of both Vit. D2 and Vit. D3 in the liver. It has a half-life of 2–3 weeks [7]. A second hydroxylation process occurs in the kidneys to form the biologically active form, which is the 1,25 (OH)2D, which has a half-life of ∼4 h. The 1,25 (OH)2D is under regulation by serum levels of calcium, phosphate, and parathyroid hormone [5].
Vit. D receptors are present in nearly all body tissues and systems: adipose tissue, cardiovascular system, thyroid and parathyroid, renal system, immune system, central nervous system, pancreas, gastrointestinal system, and the reproductive system [8],[9]. Moreover, Vit. D receptors are present in human sperms (nucleus and mid-piece parts), spermatids as well as epididymis, seminal vesicle, testicular tissue, and prostate [10],[11].
Studies claimed that Vit. D-deficient persons are liable to experience diseases such as dementia, malignancies, thyroid dysfunction, autoimmune diseases, diabetes mellitus, as well as cardiac diseases [12],[13].
AimWe designed the study to assess both seminal and serum Vit. D levels in Egyptian males and to establish the relation between both serum and seminal Vit. D and the age, residence, education, marital and fertility states, and semen parameters of men in our community.
Patients and methodsA cross-sectional hospital-based study was performed at the Department of Dermatology, Venereology, and Andrology in collaboration with the Department of Clinical Pathology, Assiut University Hospital, Assiut, Egypt. We included 100 male patients who went to the andrology clinic during the period from May 2019 till August 2019. The study protocol was approved by the Assiut Medical School Ethical Review Board (Ethical Committee N: IRB17100441). All participants signed an informed consent before inclusion in the study.
We excluded patients with varicocele grade 3, patients with genital tract infection, patients with primary or secondary hypogonadism, patients on hormonal therapy (e.g. testosterone in the past 6 months), patients on calcium and Vit. D supplement, diseases or drugs affecting Vit. D absorption, and patients with hepatic or renal failure.
All patients were assessed and interviewed for their medical history, including name, age, marital state, occupation, special habits, sun exposure, sunscreen usage, and Vit. D or calcium supplement. Meticulous clinical examination, including general examination such as height and weight, as well as genital examination, such as penis, testes (size, shape, and consistency), scrotum, and pubic hair, was performed for each patient.
Venous blood samples from all patients were collected via venipuncture of superficial vessels in the antecubital fossa or hands by a trained clinician, and then centrifuged at 5000g for 10 min, and serum was transferred in an ice box between two dried ice pack fixed tightly and frozen at −30°C for a maximum of 12 months before Vit. D measurement. The levels of Vit. D were measured by enzyme-linked immunosorbent assay using a Best 2000 serial no. IDXC3054, according to manufacturer’s protocol.
Reference range
The reference range for Vit. D was as follows:
Deficient: less than 10 ng/ml.Insufficient: 10–30 ng/ml.Sufficient: 30–100 ng/ml.Intoxication: more than 100 ng/ml.After an abstinence period of 2–7 days, the semen sample of each patient was collected in a plastic container and evaluated by two andrologists using WHO guidelines 2010 as a reference [14].
After completing the conventional semen analysis, the semen sample was transferred through an ice box between two dried ice packs fixed tightly and frozen at −30°C for a maximum of 12 months before Vit. D measurement. The levels of Vit. D were measured using a 25(OH) Vit. D enzyme-linked immunosorbent assay kit for quantitative determination of total 25(OH) Vit. D in human serum, plasma, tissue homogenates, and other biological fluids (Best 2000 serial no. IDXC3054) according to manufacturer’s protocol.
Reference range
The reference range for Vit. D was as follows:
Deficient: less than 10 ng/ml.Insufficient: 10–29 ng/ml.Sufficient: 30–100 ng/ml.Potential toxicity: more than 100 ng/ml.Statistical analysis
The data were analyzed using the Statistical Package of the Social Sciences (SPSS.11.0; SPSS Inc., Chicago, Illinois, USA) software program. Data were statistically stated in terms of range, mean, SD, median, frequencies (number of cases), and relative frequencies (percentages) when appropriate. A comparison of quantitative data between different groups in the present study was done using Student t test and analysis of variance for the independent sample when normally distributed and Mann–Whitney U test for an independent sample when not normally distributed. Comparisons of the categorical variables were made by the χ2 test. A P value less than 0.05 was considered statistically significant.
ResultsThe study included 100 male participants. Their age ranged from 20.0 to 50.0 years, with a mean±SD of 34.97±8.37 years. Most of them were from rural areas of Upper Egypt (60 vs. 40% from urban areas). Moreover, most of them were smokers (58 vs. 42% nonsmokers). Other demographic and clinical data are illustrated in [Table 1].
Regarding the fertility state of all participants, of the 81 married persons, 47 (58%) persons were fertile, whereas the remaining 34 (42%) were infertile. Primary infertility was present in 26 (32.1%) persons and secondary infertility was present in eight (9.9%) persons. We classified participants according to their semen analysis results into six categories ([Figure 1]). Most of the participants (29%) had asthenozoospermic semen analysis.
Figure 1 Distribution of participants according to their semen analysis results.Regarding the serum level of Vit. D in all participants, it was ranged from 2.7 to 71.2, with a mean±SD of 42.00±18.94. Only four (4%) participants had deficient serum Vit. D level, whereas 25 (25%) participants had insufficient serum Vit. D level, and the remaining 71 (71%) participants had sufficient serum Vit. D level ([Table 2]). Moreover, seminal level of Vit. D in all participants was ranged from 18.0 to 101.0, with a mean±SD of 47.48±20.53. Only 17 (17%) participants had insufficient seminal Vit. D level, whereas 83 (83%) participants had sufficient seminal Vit. D level ([Table 2]).
[Table 3] illustrates the correlation between serum Vit. D level and semen parameters. A nonsignificant inverse correlation was obtained between serum Vit. D level and the presence of abnormal forms in all participants. Nonsignificant positive correlations were observed between serum Vit. D level and other semen parameters (semen volume, total sperm count, sperm concentration, and sperm progressive motility).
Table 3 Correlation between serum vitamin D level and semen parameters in all participantsRegarding correlation between seminal Vit. D level and semen parameters, a nonsignificant inverse correlation was obtained between seminal Vit. D level and the presence of abnormal forms, whereas a nonsignificant positive correlation was observed between seminal Vit. D level and other semen parameters (semen volume, total sperm count, sperm concentration, and sperm progressive motility) ([Table 4]).
Table 4 Correlation between seminal vitamin D level and semen parameters in all participantsA nonsignificant relation was obtained between serum Vit. D level and age, residence, education, smoking, and marital and fertility state of all participants ([Table 5]). In addition, a nonsignificant relation was obtained between seminal Vit. D level and the aforementioned factors ([Table 6]).
Table 5 Relation between serum vitamin D level and demographic and clinical data of all participantsTable 6 Relation between seminal vitamin D level and demographic and clinical data of all participants DiscussionIn the current study, we searched Vit. D level (both serum and seminal) in men attending the andrology clinic with various complaints during a specific period of time and analyzed its relation to the age, residence, education, smoking, marital and fertility states, and semen parameter indices of men in our community.
It is well known that level of Vit. D varies among different populations, owing to the variations in sun exposure, clothing style, skin color, latitude, and diet [15].
The prevalence of Vit. D deficiency has been increased in the past few decades [16]. Globally, one billion persons experience Vit. D deficiency [17]. In tropical countries, the prevalence of serum vitamin D deficiency has a value between 30 and 93%. It considered one of the major health problems in both developed and developing countries [18].
In the present study, only four (4%) persons had deficient serum Vit. D level, whereas 25 (25%) persons had insufficient serum Vit. D level and the remaining 71 (71%) persons had sufficient serum Vit. D level. Moreover, only 17 (17%) persons had insufficient seminal Vit. D level, whereas 83 (83%) persons had sufficient seminal Vit. D level. These results are attributed to the fact that most people in Upper Egypt are farmers and are subjected to the daily sunny climate of our country.
An Iranian study by Abbasihormozi et al. [19] found that Vit. D deficiency, insufficiency, and normal levels were observed in 8.6, 43.6, and 47.8% of Iranian participants, respectively. This difference might be owing to the aforementioned climatic and occupational factors, and also differences in the genetic and racial factors. Moreover, we had performed the study during summer months when the Vit. D level is at its maximum level.
Many research studies on both animals and human claimed that Vit. D has an important role in human reproduction [6],[10],[11], and this was in contrast to the results of the current research.
Surprisingly, in the current research, we found that both serum and seminal Vit. D levels had nonsignificant correlations between their levels and all semen parameters. Nonsignificant inverse correlation was obtained between serum and seminal Vit. D levels and the presence of abnormal forms. However, nonsignificant positive correlations were observed between serum Vit. D level and other semen parameters (semen volume, total sperm count, sperm concentration, and sperm progressive motility).
A closer study by Jueraitetibaike et al. [20] on 222 males, which was performed to evaluate the associations of semen quality with both serum and seminal plasma Vit. D levels, found that seminal Vit. D level showed no relationship with serum Vit. D level, whereas it was inversely associated with sperm concentration and positively correlated with semen volume and sperm kinetic values.
A Danish study by Sood et al. [21] suggests that higher Vit. D levels are associated with decrease in both sperm count and percentage of normal sperm morphology. However, their study was done on rats.
Ao et al. [22] claimed that the administration of 1,25(OH)2 D3 has been associated with increase in sperm motility and acrosin activity, supporting its role in fertilization capacity.
Kwiecinski et al. [23] conducted the first study indicating the effect of Vit. D on reproduction, but it was conducted on rats. They divided male rats into a Vit. D-sufficient group and a Vit. D-deficient group and observed the outcome of mating with female rats. They claimed that Vit. D-deficient group had lower mating rates, fertility rates, and birth rates. Then multiple studies proved the relation between Vit. D and human reproductive functions [24],[25].
Blomberg Jensen et al. [25] studied 300 Danish men and found a positive correlation between serum Vit. D and sperm motility. Similarly, Tirabassi et al. [13] in their study on 104 patients also found a positive correlation between Vit. D and both total and progressive sperm motility. A Chinese study by Yang et al. [26] claimed that sufficient Vit. D males had more motile sperms than deficient males.
All these results were in contrast to our results and the results of an Iranian study by Abbasihormozi et al. [19] in their research on subfertile men, as they found that serum Vit. D levels had no relationship with semen parameters in fertile persons, whereas in persons with oligoasthenozoospermic and teratozoospermic semen analysis, a positive correlation was obtained between Vit. D level and sperm viability. Moreover, they found a positive correlation between Vit. D level and sperm motility in OAT group. They concluded that Vit. D deficiency probably has a direct effect on sperm motility in OAT men. They also stated that whether Vit. D levels is associated with altered male infertility remains controversial and is not documented.
Moreover, Ramlau-Hansen et al. [27] in their study found that high Vit. D level was unexpectedly associated with lower crude median total sperm count and percentage of normal sperm morphology. However, they concluded that their results do not indicate that low Vit. D is a risk factor for poor semen quality in young healthy men, but they owed this to the small number of men with low Vit. D levels to detect an effect.
Hammoud et al. [28] claimed that excessive (≥50 ng/ml) as well as deficient (<20 ng/ml) serum Vit. D levels were associated with decline in sperm count and progressive motility. They found that men with Vit. D levels between 20 and 50 ng/ml exhibited maximal values of semen parameters. However, males with Vit. D levels above 50 ng/ml showed lower percent normal sperm head, percent progressive motile sperm, sperm concentration, and total progressive motile sperm count, and men with Vit. D level less than 20 ng/ml had lower total sperm count and total progressive motile sperm.
The result of the present study was in contrast to most of the research studies regarding the effect of Vit. D on semen parameters and fertility in males; however, it was close to the results of Abbasihormozi et al. [19] and his colleagues in their study on Iranian subfertile men, the results of Ramlau-Hansen et al. [27], and the results of Sood et al. [21].
In the current study, we obtained nonsignificant relations between both serum and seminal Vit. D level and age, residence, education, smoking, and marital and fertility state of all participants.
Herein, we disputed the role of Vit. D in fertility, and also, we deny its relation to semen parameters and to the following indices: age, residence, education, smoking, and marital state. The small number of Vit. D-deficient patients in the present study may be the cause of such results.
The limitations of our study are the relatively small number of included participants; the small number of Vit. D-deficient persons, which is attributed to the fact that most people in Upper Egypt are farmers and are subjected to the daily sunny climate; the whole study has been performed during summer months; and the lack of hormonal investigations of the participants.
We do recommend further Egyptian studies on a larger sample of Vit. D-deficient people to prove or disprove our assumption. Moreover, we recommend adding hormonal profile to the methodology of the future research studies.
ConclusionAs most Egyptian males are subjected to sunny climate of our country, the prevalence of Vit. D deficiency is low both in serum and seminal fluid. The results of the current study did not support any evidence for the role of Vit. D in semen parameters or male fertility status.
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Conflicts of interest
There are no conflicts of interest.
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