Vitamin C Deficiency and Depletion in the United States: The Third National Health and Nutrition Examination Survey, 1988 to 1994

Hampl, Jeffrey S; Taylor, Christopher A.; Johnston, Carol S.

doi:10.2105/ajph.94.5.870

Cited by 177 publications

(136 citation statements)

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“…21,31 Although a relationship between male infertility and systemic antioxidant deficiency has not been reported to date, it is possible that a subset of infertile men may be at risk for antioxidant deficiency, particularly, vitamin C deficiency. 32 We suspect that infertile men with specific lifestyles (e.g., smoking, increased alcohol intake and dieting) may be at high risk for antioxidant or vitamin deficiency, but this remains to be tested. 33,34 Recently, investigators evaluated dietary antioxidant intake (vitamins C, E or b-carotene) and sperm DNA damage in a cohort of fertile men, but failed to identify any relationships between these parameters.…”

Section: 14mentioning

confidence: 99%

Antioxidant therapy in male infertility: fact or fiction?

Zini¹,

Alhathal²

2011

Asian J Androl

110

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Infertile men have higher levels of semen reactive oxygen species (ROS) than do fertile men. High levels of semen ROS can cause sperm dysfunction, sperm DNA damage and reduced male reproductive potential. This observation has led clinicians to treat infertile men with antioxidant supplements. The purpose of this article is to discuss the rationale for antioxidant therapy in infertile men and to evaluate the data on the efficacy of dietary and in vitro antioxidant preparations on sperm function and DNA damage. To date, most clinical studies suggest that dietary antioxidant supplements are beneficial in terms of improving sperm function and DNA integrity. However, the exact mechanism of action of dietary antioxidants and the optimal dietary supplement have not been established. Moreover, most of the clinical studies are small and few have evaluated pregnancy rates. A beneficial effect of in vitro antioxidant supplements in protecting spermatozoa from exogenous oxidants has been demonstrated in most studies; however, the effect of these antioxidants in protecting sperm from endogenous ROS, gentle sperm processing and cryopreservation has not been established conclusively. Keywords: antioxidant; male infertility; oxidative stress; sperm DNA fragmentation; vitamins RELATIONSHIP BETWEEN OXIDATIVE STRESS AND SPERM DYSFUNCTION Seminal oxidative stress (OS) results from an imbalance between reactive oxygen species (ROS) production and ROS scavenging by seminal antioxidants. Seminal OS is believed to be one of the main factors in the pathogenesis of sperm dysfunction and sperm DNA damage in male infertility.1-4 Indeed, it is estimated that 25% of infertile men possess high levels of semen ROS, whereas fertile men do not have high levels of semen ROS.1,4-6 Although a controlled production of these ROS is required for sperm physiology (sperm hyperactivation, capacitation and acrosome reaction) and for natural fertilization, [7][8][9] the excessive production of ROS by immature germ cells and leukocytes causes sperm dysfunction (lipid peroxidation, loss of motility and sperm DNA damage). 9,10 Spermatozoa are particularly susceptible to oxidative injury due to the abundance of plasma membrane polyunsaturated fatty acids. [10][11][12] These unsaturated fatty acids provide fluidity that is necessary for membrane fusion events (e.g., the acrosome reaction and sperm-egg interaction) and for sperm motility. However, the unsaturated nature of these molecules predisposes them to free radical attack and ongoing lipid peroxidation throughout the sperm plasma membrane. Once this process has been initiated, accumulation of lipid peroxides occurs on the sperm surface (this results in loss of sperm motility) and oxidative damage to DNA can ensue. 13,14SEMINAL ANTIOXIDANT CAPACITY AND SPERM DYSFUNCTION Seminal plasma and spermatozoa themselves are well endowed with an array of protective antioxidants to protect spermatozoa from OS, especially, at the post-testicular level. 6,15,16 Seminal plasma contains a number of high-molecular weigh...

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Section: 14mentioning

confidence: 99%

Antioxidant therapy in male infertility: fact or fiction?

Zini¹,

Alhathal²

2011

Asian J Androl

110

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“…Smokers require higher doses of vitamin C (110-125 mg/day) compared with normal population's requirement of 60-90 mg/day because of increased demand as a result of increased oxidative stress. 6 Some researchers feel that the elderly require more vitamin C for the same reason. 6,17,18,24 The micronutrient and macronutrient deficiencies in the geriatric population cause new cases of scurvy, pellagra, and Zn deficiency.…”

Section: Discussionmentioning

confidence: 99%

“…6 Some researchers feel that the elderly require more vitamin C for the same reason. 6,17,18,24 The micronutrient and macronutrient deficiencies in the geriatric population cause new cases of scurvy, pellagra, and Zn deficiency. 8,14,16 This patient showed classical symptoms of bleeding caused by vitamin C deficiency: petechiae, hematomas, weakness, anemia, as well as radiologic bone changes, giving a typical picture of scurvy.…”

Section: Discussionmentioning

confidence: 99%

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Scurvy Is Still Present in Developed Countries

et al. 2008

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“…Although scurvy is generally regarded as a nutritional problem, only ±17% of the variance of the serum vitamin C concentration can be explained by vitamin C intake, as presented in the Third National Health and Nutrition Examination Survey. The influence of dietary vitamin C on serum ascorbic acid measurements in this study was complicated by the use of food frequency questionnaires that poorly report vitamin C levels (Hampl et al 2004).…”

mentioning

confidence: 97%

Vitamin C deficiency: more than just a nutritional disorder

et al. 2011

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Although vitamin C deficiency and scurvy are generally considered as pure nutritional disorders, only a minority of the vitamin C concentration is determined by food intake. In the presence of transition metals (iron and copper), the antiscorbutic factor shifts from an antioxidant to a pro-oxidant function. Haptoglobin (Hp) is a plasma a-2 glycoprotein characterized by 3 common phenotypes (Hp 1-1, Hp 2-1 and Hp 2-2). Its free hemoglobin (Hb)-binding capacity prevents Hb-driven oxidative damage. When the antioxidant capacity of Hp is insufficient, its role is taken over by hemopexin (heme-binding protein) and by vitamin C (free radical scavenger). The Hp 2-2 phenotype has a lower capacity to inhibit oxidation and vitamin C depletion. In this article, two consequences of this major finding are tackled. The Hp polymorphism is an important non-nutritional modifying factor in the pathogenesis of vitamin C deficiency and scurvy, which may explain the success of long-range human migration by the natural selection of some populations characterized by high Hp 1 allele frequencies. Moreover, we propose tailoring the recommended dietary allowance (RDA) values of vitamin C, taking into consideration the Hp phenotype dependency.

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Vitamin C Deficiency and Depletion in the United States: The Third National Health and Nutrition Examination Survey, 1988 to 1994

Abstract: Health professionals should recommend consumption of vegetables and fruits rich in vitamin C and should recommend supplementation for individuals at risk of vitamin C deficiency.

Cited by 177 publications

References 52 publications

Antioxidant therapy in male infertility: fact or fiction?

Antioxidant therapy in male infertility: fact or fiction?

Scurvy Is Still Present in Developed Countries

Vitamin C deficiency: more than just a nutritional disorder

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