What Do We C in Children With Scurvy? A Case Series Focused on Musculoskeletal Symptoms

OBJECTIVES

Vitamin C deficiency in children commonly presents with musculoskeletal symptoms such as gait disturbance, refusal to bear weight, and bone or joint pain. We aimed to identify features that could facilitate early diagnosis of scurvy and estimate the cost of care for patients with musculoskeletal symptoms related to scurvy.

METHODS

We conducted a retrospective chart review of patients at a single site with diagnostic codes for vitamin C deficiency, ascorbic acid deficiency, or scurvy. Medical records were reviewed to identify characteristics including presenting symptoms, medical history, and diagnostic workup. The Pediatric Health Information System was used to estimate diagnostic and hospitalization costs for each patient.

RESULTS

We identified 47 patients with a diagnosis of scurvy, 49% of whom had a neurodevelopmental disorder. Sixteen of the 47 had musculoskeletal symptoms and were the focus of the cost analysis. Three of the 16 had moderate or severe malnutrition, and 3 had overweight or obesity. Six patients presented to an emergency department for care, 11 were managed inpatient, and 3 required critical care. Diagnostic workups included MRI, computed tomography, echocardiogram, endoscopy, lumbar puncture, and/or EEG. Across all patients evaluated, the cost of emergency department utilization, imaging studies, diagnostic procedures, and hospitalization totaled $470 144 (median $14 137 per patient).

CONCLUSIONS

Children across the BMI spectrum, particularly those with neurodevelopmental disorders, can develop vitamin C deficiency. Increased awareness of scurvy and its signs and symptoms, particularly musculoskeletal manifestations, may reduce severe disease, limit adverse effects related to unnecessary tests/treatments, and facilitate high-value care.

Infantile scurvy as a consequence of agricultural intensification in the 1st millennium BCE Etruria Campana

The 1st millennium BCE in Italy was a time of agricultural intensification of staple cereal production which shaped sociocultural, political, and economic spheres of pre-Roman groups. The lifeways and foodways of the Etruscans, the greatest civilization in western Europe before Roman hegemony, are traditionally inferred from secondary written sources, funerary archaeology, archaeobotany, and zooarchaeology. However, no direct data extrapolated from the study of human skeletal remains are available to evaluate the extent to which agricultural intensification and decreased dietary diversity impacted health and the expression of skeletal indicators of metabolic disease. Macroscopic and radiological analyses were conducted on an archaeological skeletal sample of non-adults (n = 29) recovered from Pontecagnano (southern Italy) dating to the Orientalizing period (730-580 BCE). This allowed us to identify five cases of scorbutic non-adults and to assign diagnostic values to skeletal lesions of scurvy that have not been previously described in the literature. The onset of scurvy in the examined sample is related to the increased reliance of Etruscans on crops lacking vitamin C in this period of agricultural intensification. The skeletal expression of scurvy varied among the non-adults, with differences in location and disease severity; these were interpreted considering the age-at-death of the individuals coupled with feeding behaviors and interindividual variability.

Vitamin C Deficiency Deteriorates Bone Microarchitecture and Mineralization in a Sex-Specific Manner in Adult Mice

Vitamin C (VitC) is essential for bone health, and low VitC serum levels increase the risk for skeletal fractures. If and how VitC affects bone mineralization is unclear. Using micro-computed tomography (μCT), histologic staining, as well as quantitative backscattered electron imaging (qBEI), we assessed the effects of VitC on femoral structure and microarchitecture, bone formation, and bone mineralization density distribution (BMDD) in the VitC incompetent Gulo-/- mouse model and wild-type mice. In particular, VitC-supplemented, 20-week-old mice were compared with age-matched counterparts where dietary VitC intake was excluded from week 15. VitC depletion in Gulo-/- mice severely reduced cortical thickness of the diaphyseal shaft and bone volume around the growth plate (eg, bone volume of the primary spongiosa -43%, p < 0.001). Loss of VitC also diminished the amount of newly formed bone tissue as visualized by histology and calcein labeling of the active mineralization front. BMDD analysis revealed a shift to higher calcium concentrations upon VitC supplementation, including higher average (~10% increase in female VitC deficient mice, p < 0.001) and peak calcium concentrations in the epiphyseal and metaphyseal spongiosa. These findings suggest higher bone tissue age. Importantly, loss of VitC had significantly more pronounced effects in female mice, indicating a higher sensitivity of their skeleton to VitC deficiency. Our results reveal that VitC plays a key role in bone formation rate, which directly affects mineralization. We propose that low VitC levels may contribute to the higher prevalence of bone-degenerative diseases in females and suggest leveraging this vitamin against these conditions. © 2023 American Society for Bone and Mineral Research (ASBMR).

Technical note: The use and misuse of threshold diagnostic criteria in paleopathology

Weighted threshold diagnostic criteria approaches have emerged for diseases that involve skeletal/bony tissue that are readily diagnosed in the field of paleopathology such as Vitamin C deficiency (scurvy), Vitamin D deficiency (rickets) and treponemal disease. These criteria differ from traditional differential diagnosis in that they involve standardized inclusion criteria based on the lesion's specificity to the disease. Here I discuss the limitations and benefits of threshold criteria. I argue that while these criteria will benefit from further revision such as inclusion of lesion severity, and the incorporation of exclusion criteria, threshold diagnostic approaches have considerable value in the future of diagnosis in the field.

Release of SMP30 in Extracellular Vesicles under Conditions of Ascorbic Acid Deficiency Is Involved with Acute Phase Response in ODS Rat

Senescence marker protein-30 (SMP30) is a senescence marker molecule that exhibits lactonase activity in the ascorbic acid (AsA) biosynthesis pathway, except in primate mammals, including humans. Although numerous studies have shown that hepatic AsA deficiency causes acute-phase responses, details of the relationship between SMP30 expression and acute-phase responses in AsA-deficient conditions remain to be elucidated. Here, we investigated the effects of AsA deficiency on the relationship between SMP30 and acute liver injury in osteogenic disorder Shionogi (ODS) rats, which have a hereditary defect in AsA biosynthesis. Male-ODS rats (4 wk old) were pair-fed an AsA-free diet with distilled or 0.1% AsA-dissolved water for 14 d. Under AsA-deficient conditions, hepatic SMP30 protein level was decreased and liver injury markers, the serum aspartate aminotransferase/alanine transaminase ratio and cytokine-induced neutrophil chemoattractant-1 (CINC-1) concentration, were elevated. In contrast, SMP30 protein level in extracellular vesicles (EVs) was significantly increased in addition to the positive acute proteins haptoglobin and asialoglycoprotein receptor 1 (ASGPR1), hepatic-derived specific markers expression under AsA-deficient conditions. AsA deficiency also activated signal transducer and activator of transcription 3 (STAT3) which is linked to EVs release in the liver. These results suggest that the release of SMP30 in EVs by AsA deficiency is involved with acute-phase responses.

The Role of Vitamin Deficiency in Liver Disease: To Supplement or Not Supplement?

Over the past few years, growing interest has been shown for the impact of dietary requirements and nutritional factors on chronic diseases. As a result, nutritional programs have been reinforced by public health policies. The precise role of micronutrients in chronic liver disease is currently receiving particular attention since abnormalities in vitamin levels are often detected. At present, treatment programs are focused on correcting vitamin deficiencies, which are frequently correlated to higher rates of comorbidities with poor outcomes. The literature reviewed here indicates that liver diseases are often related to vitamin disorders, due to both liver impairment and abnormal intake. More specific knowledge about the role of vitamins in liver disease is currently emerging from various results and recent evidence. The most significant benefits in this area may be observed when improved vitamin intake is combined with a pharmacological treatment that may also affect the progression of the liver disease, especially in the case of liver tumors. However, further studies are needed.

Radiation-induced gastrointestinal syndrome is exacerbated in vitamin C-insufficient SMP30/GNL knockout mice

OBJECTIVES

Accidental exposure to high-dose radiation causes life-threatening acute radiation syndrome, features that include gastrointestinal syndrome (GIS) and hematopoietic syndrome (HS). Administration of vitamin C (VC), a free radical scavenger, has been reported to increase survival of mice in GIS and HS models. The effect of nutritional VC status on radiation injury remains unknown because, unlike humans, mice can synthesize VC. The aim of this study was to investigate the effect of VC insufficiency on acute radiation syndrome using senescence marker protein 30 (SMP30)/gluconolactonase knockout (SMP30-KO) mice.

METHODS

SMP30-KO mice, which cannot synthesize VC, were given water with or without sufficient VC supplementation, and were analyzed in GIS and HS models.

RESULTS

In the GIS model, in which bone marrow failure is rescued by bone marrow transplantation, VC-insufficient mice had a lower survival rate than VC-sufficient mice. The intestine of VC-insufficient GIS mice showed epithelial cell atrophy, inflammatory cell infiltration, and decreased crypt cell proliferation. We observed rapid VC oxidation after total body irradiation in the intestine of mice supplemented with VC-sufficient water. In the HS model, which was not combined with bone marrow transplantation, there was no difference in survival between VC-insufficient and -sufficient mice.

CONCLUSION

The results of this study demonstrated that nutritionally sufficient VC exerts a radioprotective effect against radiation-induced GIS.

Scurvy Masquerading as Juvenile Idiopathic Arthritis or Vasculitis with Elevated Inflammatory Markers: A Case Series

Ten patients with scurvy were evaluated by rheumatology; we review their clinical, laboratory, and dietary presentations. Eight patients had developmental delay or autism. All had elevated inflammatory markers. These clinical and laboratory features with imaging findings can mimic rheumatic conditions such as arthritis, vasculitis, and chronic nonbacterial osteomyelitis (CNO).

Plasma Vitamin C Levels: Risk Factors for Deficiency and Association with Self-Reported Functional Health in the European Prospective Investigation into Cancer-Norfolk

BACKGROUND

To investigate the demographic and lifestyles factors associated with vitamin C deficiency and to examine the association between plasma vitamin C level and self-reported physical functional health.

METHODS

A population-based cross-sectional study using the European Prospective Investigation into Cancer-Norfolk study. Plasma vitamin C level < 11 µmol/L indicated vitamin C deficiency. Unconditional logistic regression models assessed the association between vitamin C deficiency and potential risk factors. Associations between quartiles of vitamin C and self-reported functional health measured by the 36-item short-form questionnaire (SF-36) were assessed.

RESULTS

After adjustment, vitamin C deficiency was associated with older age, being male, lower physical activity, smoking, more socially deprived area (Townsend index) and a lower educational attainment. Compared to the highest, those in the lowest quartile of vitamin C were more likely to score in the lowest decile of physical function (adjusted odds ratio (aOR): 1.43 (95%CI: 1.21-1.70)), bodily pain (aOR: 1.29 (95% CI: 1.07-1.56)), general health (aOR: 1.4 (95%CI: 1.18-1.66)), and vitality (aOR: 1.23 (95%CI: 1.04-1.45)) SF-36 scores.

CONCLUSIONS

Simple public health interventions should be aimed at populations with risk factors for vitamin C deficiency. Poor self-reported functional health was associated with lower plasma vitamin C levels, which may reflect symptoms of latent scurvy.

Severe Gingivitis Associated with Ascorbic Acid-Deficiency in a Pediatric Patient

Plaque-induced gingivitis, a common condition in children, responds well to proper oral hygiene practices. Persistent severe gingivitis, on the other hand, should prompt investigation of etiological factors. Nutritional elements are implicated in periodontal health. This case report describes a pediatric patient with severe persistent gingivitis caused by vitamin C deficiency. The events that led to a diagnosis of scurvy and a resolution of the systemic and localized manifestations of the disease, after vitamin C administration, are presented. It is recommended that vitamin C deficiency be considered in cases of refractory gingivitis, especially in pediatric patients with special health care needs who have aversion to foods rich in ascorbic acid.

Vitamin C Deficiency Reduces Muscarinic Receptor Coronary Artery Vasoconstriction and Plasma Tetrahydrobiopterin Concentration in Guinea Pigs

Vitamin C (vitC) deficiency is associated with increased cardiovascular disease risk, but its specific interplay with arteriolar function is unclear. This study investigates the effect of vitC deficiency in guinea pigs on plasma biopterin status and the vasomotor responses in coronary arteries exposed to vasoconstrictor/-dilator agents. Dunkin Hartley female guinea pigs (n = 32) were randomized to high (1500 mg/kg diet) or low (0 to 50 mg/kg diet) vitC for 10-12 weeks. At euthanasia, coronary artery segments were dissected and mounted in a wire-myograph. Vasomotor responses to potassium, carbachol, sodium nitroprusside (SNP), U46619, sarafotoxin 6c (S6c) and endothelin-1 (ET-1) were recorded. Plasma vitC and tetrahydrobiopterin were measured by HPLC. Plasma vitC status reflected the diets with deficient animals displaying reduced tetrahydrobiopterin. Vasoconstrictor responses to carbachol were significantly decreased in vitC deficient coronary arteries independent of their general vasoconstrictor/vasodilator capacity (p < 0.001). Moreover, in vitC deficient animals, carbachol-induced vasodilator responses correlated with coronary artery diameter (p < 0.001). Inhibition of cyclooxygenases with indomethacin increased carbachol-induced vasoconstriction, suggesting an augmented carbachol-induced release of vasodilator prostanoids. Atropine abolished carbachol-induced vasomotion, supporting a specific muscarinic receptor effect. Arterial responses to SNP, potassium, S6c, U46619 and ET-1 were unaffected by vitC status. The study shows that vitC deficiency decreases tetrahydrobiopterin concentrations and muscarinic receptor mediated contraction in coronary arteries. This attenuated vasoconstrictor response may be linked to altered production of vasoactive arachidonic acid metabolites and reduced muscarinic receptor expression/signaling.

Maternal vitamin C deficiency during pregnancy persistently impairs hippocampal neurogenesis in offspring of guinea pigs

While having the highest vitamin C (VitC) concentrations in the body, specific functions of VitC in the brain have only recently been acknowledged. We have shown that postnatal VitC deficiency in guinea pigs causes impairment of hippocampal memory function and leads to 30% less neurons. This study investigates how prenatal VitC deficiency affects postnatal hippocampal development and if any such effect can be reversed by postnatal VitC repletion. Eighty pregnant Dunkin Hartley guinea pig dams were randomized into weight stratified groups receiving High (900 mg) or Low (100 mg) VitC per kg diet. Newborn pups (n = 157) were randomized into a total of four postnatal feeding regimens: High/High (Control); High/Low (Depleted), Low/Low (Deficient); and Low/High (Repleted). Proliferation and migration of newborn cells in the dentate gyrus was assessed by BrdU labeling and hippocampal volumes were determined by stereology. Prenatal VitC deficiency resulted in a significant reduction in postnatal hippocampal volume (P<0.001) which was not reversed by postnatal repletion. There was no difference in postnatal cellular proliferation and survival rates in the hippocampus between dietary groups, however, migration of newborn cells into the granular layer of the hippocampus dentate gyrus was significantly reduced in prenatally deficient animals (P<0.01). We conclude that a prenatal VitC deficiency in guinea pigs leads to persistent impairment of postnatal hippocampal development which is not alleviated by postnatal repletion. Our findings place attention on a yet unrecognized consequence of marginal VitC deficiency during pregnancy.

Antioxidant vitamin levels in sickle cell disorders

BACKGROUND

Sickle cell disorder is a haemoglobinopathy prevalent in the Vidharbha region of Maharashtra, central India. With recent evidence of oxidative stress in sickle haemoglobinopathy, a possible deficiency of antioxidant vitamins was suspected.

METHODS

We measured plasma vitamin E, vitamin C and beta-carotene levels in persons with heterozygous (n=80) and homozygous sickle cell state (n=20), and suitable healthy controls for these groups (n=100 and 66, respectively) in a community-based study in the villages near our institution.

RESULTS

Subjects with heterozygous sickle cell trait had lower vitamin E levels than their respective controls (p < 0.05). Subjects with homozygous sickle cell disease had lower levels of all three vitamins (p < 0.05). Vitamins E and C levels showed a significant positive correlation in both forms of sickle cell disorder.

CONCLUSION

Our findings suggest that there is depletion of the antioxidant vitamins, particularly in severe forms of sickle cell disorder. A trial of administration of therapeutic doses of vitamin E in this condition is warranted.

Stress and nutrition in relation to excess development of chronic disease in Puerto Rican adults living in the Northeastern USA

Although health disparities are well documented among minority populations, they have not been fully explained by socio-economic status. We have demonstrated that Puerto Rican elders in Massachusetts are significantly more likely to have physical disability, depression, cognitive impairment, diabetes and other chronic health conditions than do non-Hispanic white elders living in the same neighborhoods. This suggests that the disparity is not due only to physical or neighborhood location, and that other factors must be influencing these differences. In that study, we also showed that the Puerto Rican elders had diets that were limited in diversity and were relatively low in micronutrient content. In our ongoing cohort study within our Boston Puerto Rican Center for Population Health and Health Disparities, we are investigating the relationships between psychosocial stress, its effect on physiologic burden or "allostatic load" and, in turn, how this is associated with the functional outcomes previously identified as areas of health disparity: depression, cognitive impairment and functional limitation. We further propose that the association between life stress, physiologic response and chronic conditions is modified by nutritional status, with a focus on B vitamins and antioxidant vitamins.

Alpha-tocopherol downregulates gulonolactone oxidase activity in sturgeon

Gulonolactone oxidase (GLO) is the enzyme responsible for the last step of ascorbic acid biosynthesis. The aim of this study was to investigate the effect of dietary alpha-tocopherol and ascorbic acid on GLO activity in a lower vertebrate, the white sturgeon (Acipenser transmontanus). Both alpha-tocopherol and ascorbic acid modulated renal GLO activity. The increase of dietary levels of alpha-tocopherol and/or ascorbic acid significantly raised the liver concentrations of these two antioxidants and concomitantly lowered kidney's GLO activity. The results suggest that the enzyme of ascorbic acid synthetic pathway responded to the animal's antioxidant status and that its activity was downregulated by alpha-tocopherol. This is the first record of alpha-tocopherol being involved in the regulation of ascorbic acid synthesis. This new observation may provide a hypothesis for the evolutionary loss of GLO expression in teleost fishes.

Elevated levels of S-nitrosoalbumin in preeclampsia plasma

The availability of nitric oxide (NO), which is required for the normal regulation of vascular tone, may be decreased in preeclampsia, thus contributing to the vascular pathogenesis of this pregnancy disorder. Because ascorbate is essential for the decomposition of S-nitrothiols and the release of NO, we speculated that the ascorbate deficiency typical of preeclampsia plasma might result in decreased rates of decomposition of S-nitrosothiols. We tested the hypothesis that total S-nitrosothiol and S-nitrosoalbumin concentrations are increased in preeclampsia plasma, reflecting a decreased release of NO from these major reservoirs of NO. Gestationally matched plasma samples were obtained (before labor or intravenous MgSO(4)) from 21 women with preeclampsia and 21 women with normal pregnancy, and plasma samples were also obtained from 12 nonpregnant women of similar age and body mass index during the follicular phase of the menstrual cycle. All were nonsmokers. The assay included ultraviolet-induced decomposition of S-nitrosothiols to liberate NO captured by a florigenic reagent, 4,5-diaminofluoresceine, to produce diaminofluoresceine-Triazole. Preeclampsia plasma contained significantly higher concentrations of total S-nitrosothiols (11.1+/-2.9 nmol/mL) than normal pregnancy samples (9.4+/-1.5 nmol/mL). Even greater differences were found between preeclampsia plasma and plasma samples from normal pregnancies and nonpregnant women (294+/-110, 186+/-25, and 151+/-25 pmol/mg protein, respectively) when S-nitrosothiol content was expressed per milligram protein. The albumin fraction contained 49.4% of total plasma S-nitrosothiols in the control samples and 53.7% and 56.8% of plasma S-nitrosothiols in normal pregnancy and preeclampsia, respectively. The level of S-nitrosoalbumin was significantly higher in preeclampsia than in normal pregnancy or nonpregnancy plasma (6.3+/-1.4, 5.1+/-0.7, and 4.2+/-1.0 nmol/mL, respectively). The increased concentration of S-nitrosoalbumin in preeclampsia almost completely accounted for the increased levels of S-nitrosothiols in total plasma. Due to combined increases in nitrosothiols and decreases in protein, the preeclampsia plasma concentration of S-nitrosoalbumin was greatly increased on a per milligram of protein basis (271% and 186% compared with normal nonpregnancy and normal pregnancy plasma, respectively). We conclude that S-nitrosoalbumin and total S-nitrosothiol concentrations are significantly increased in preeclampsia plasma and may reflect insufficient release of NO groups in this condition.

Role of biological antioxidants in benzanthrone toxicity

Previous studies indicate that benzanthrone, an anthraquinone dye intermediate, caused significant depletion of ascorbic acid (AsA). In this investigation the effect of benzanthrone on the status of different forms of AsA and other bio-antioxidants such as glutathione (GSH) was studied. Oral administration of benzanthrone (50, 125 or 250 mg/kg body weight) resulted in a significant increase of urinary AsA levels with a concomitant decrease in the urinary dehydroascorbic acid (DHA) content in both rats and guinea-pigs. Benzanthrone caused a dose-dependent decrease in hepatic, adrenal and serum AsA levels with a subsequent increase in DHA and diketogulonic acid (DKA) levels in both rats and guinea-pigs. Following benzanthrone treatment, rats showed an increase in the scorbutic index (to 1.01-1.21) of the liver, adrenal glands and serum compared to controls (0.12-0.24). The scorbutic indices of liver, adrenal glands and serum were also substantially increased (to 3.61-11.20) in benzanthrone-treated guinea-pigs compared to controls (0.16-0.38). Single oral administration of benzanthrone to guinea-pigs caused a dose-dependent depletion of GSH in liver (15-51%), adrenal glands (27-64%) and serum (32-86%). Furthermore, the depletion of GSH by benzanthrone in rats was of a lesser degree. This suggests that continued exposure of guinea-pigs to benzanthrone may lead to scurvy-type changes in this animal species but not to the same extent in rats, since the latter has the enzymatic capacity to synthesise AsA. Therefore, it can be hypothesised that benzanthrone per se, or its metabolites, interact with reduced GSH thereby causing its depletion. Furthermore, in order to replenish the depleted GSH levels, AsA might be oxidized to DHA and hence the decrease in AsA with the simultaneous increase in DHA was observed.

Studies on the formation of collagen. IV. Effect of vitamin C deficiency on the neutral salt-extractible collagen of skin

The skin of severely scorbutic guinea pigs which were losing weight contained no detectible neutral salt-extractible collagen. Conditions of growth (weight gain) which actively induced the formation of neutral salt-extractible collagen in the skin of normal guinea pigs failed to do so in the animal with ascorbic acid deficiency. No excess of non-collagenous proline was found in neutral salt extracts of scorbutic skin as compared with normal. Fractionation of these extracts failed to reveal the presence of significant amounts of a soluble component containing unusual proportions of glycine and proline relative to hydroxyproline. It is concluded that deficiency of ascorbic acid either interferes with the synthesis of new collagen in intact skin or causes its destruction and removal as rapidly as it is produced.

Ketone body metabolism in ascorbic acid deficiency: in vivo utilization of ketone bodies in guinea pigs

Blood and urinary levels of ketone bodies were studied in normal, ascorbic acid-deficient, and pair-fed control, guinea pigs. The resting levels of ketone bodies in the blood and urine throughout the course of ascorbic acid-deficiency do not differ significantly from those of control animals. The ketonemic response to fasting is greater in the control animals than in the ascorbic acid-deficient animals. The disappearance of injected ketone bodies (ß-hydroxybutyrate) is decreased in the ascorbic acid-deficient animal. The data suggest that in ascorbic acid-deficiency there is a decreased utilization of ketone bodies coupled with a decreased spontaneous ketogenesis.

Probable evidence of scurvy in subadults from archeological sites in Peru

Subadult scurvy is not well documented in archeological human remains despite the existence of many biomedical references indicating that bone changes do occur in some cases and, because of this, should be observable in human burials. There are several potential reasons for this gap in our knowledge of scurvy. Not all children who suffered from scurvy died of the disease or from other causes when they had scurvy. Scurvy may not leave characteristic bone changes in every case of the disease. Some of the pathological conditions associated with scurvy have been known for many years, but these features may be rare or difficult to differentiate from other pathological conditions. Recently a lesion of the skull has been described that is probably pathognomonic for scurvy, specifically porous and sometimes hypertrophic lesions of the greater wing of the sphenoid. This lesion is bilateral and highly associated with evidence of inflammation at other anatomical sites in the skull. A survey of subadult skulls (N = 363) in the human skeletal collection from Peru at the National Museum of Natural History, Smithsonian Institution, reveals a prevalence of 10% of skulls that exhibit plausible evidence of scurvy. Some cases of scurvy also have cribra orbitalia that has been attributed to anemia. In most of the Peruvian scurvy cases, anemia is an unlikely possibility because there is no evidence of marrow hyperplasia. This highlights the need for caution in using lesions of the orbit as an indicator of anemia when there is no other evidence of this disease elsewhere in the skeleton. Anatomical evidence of scurvy offers the potential of providing new and important evidence of diet in archeological human populations.

Trace element and vitamin concentrations and losses in critically ill patients treated with continuous venovenous hemofiltration

OBJECTIVES

To measure the blood concentrations of a number of trace elements and vitamins in critically ill patients and examine their elimination by continuous venovenous hemofiltration (CVVH).

SETTING

Intensive care unit of a tertiary institution.

DESIGN

Prospective, controlled, clinical study.

PATIENTS

Eight critically ill patients requiring renal replacement therapy, nine patients requiring intensive care treatment but not requiring renal replacement therapy, and nine healthy controls.

INTERVENTIONS

Measurement of trace element and vitamin concentrations in blood and ultrafiltrate.

MEASUREMENTS AND MAIN RESULTS

Compared with normal volunteers, critically ill patients requiring CVVH had significantly lower median blood concentrations of vitamin C, vitamin E, selenium, and zinc. During the first 24 hrs of CVVH, there were no changes in the trace element and vitamin concentrations in blood, nor were there differences between pre- and postfilter samples. Micronutrient losses in the ultrafiltrate were small or undetectable except for Vitamin C, chromium, and copper. Compared with normal volunteers, critically ill patients not requiring CVVH also had significantly lower median blood concentrations of vitamin C, vitamin E, selenium, and zinc. There were no differences between the two critically ill groups.

CONCLUSIONS

The clinical significance of the reductions in blood concentrations of selenium, zinc, vitamin C, and vitamin E in critically ill patients and the ultrafiltrate losses of Vitamin C, copper, and chromium remains unclear.

Vitamin C nutriture and risk of atherosclerotic heart disease

There is substantial evidence for a role of dietary antioxidants in the prevention of cardiovascular disease, but evidence for a protective effect of vitamin C is inconclusive. Two recent reports add to the supporting evidence and provide some new observations. The first study, a 5-year prospective population study of Finnish men, suggests that vitamin C-deficient men may be at increased risk of myocardial infarction. The second study suggests that vitamin C may play a role in preventing manifestations of existing coronary artery disease, rather than in limiting disease progression. Although these results suffer from the limitations of observational studies, they provide impetus for further investigation.

Regulation of CYP1A and CYP3A mRNAs by ascorbic acid in guinea pigs

In previous studies, we found that the ascorbic acid (AsA) deficiency caused changes in the amounts of the various forms of cytochrome P450 (P450) in liver microsomes from guinea pigs in a form-specific manner. Thus, the aim of this study was to clarify whether the changes seen in the protein contents of the various forms of P450 were associated with the levels of the expression of their mRNAs. Prior to determining the mRNA level, we isolated four cDNA clones, encoding CYP1A2, CYP3A14, CYP3A15, and CYP3A17, from guinea pig liver cDNA libraries to use them as probes in further experiments. The amino acid sequence of the guinea pig CYP1A2 showed identity ranging from 73 to 77% with those of other mammalian P450s. The amino acid sequences among guinea pig CYP3As had about 94% identities with each other. The AsA deficiency apparently decreased the expression of mRNA for CYP1A1 and CYP1A2. These results were in agreement with the decrease in the content of CYP1A1 and CYP1A2 proteins. The amount of P450 protein(s) immunochemically cross-reactive with antibodies to human CYP3A4 was likely unaffected while that of human CYP3A7 tended to be decreased by the AsA deficiency. It suggested that the expression of each CYP3A isozyme was regulated differently by AsA. In fact, the level of mRNA for CYP3A14 was unaffected by the AsA deficiency, while those for CYP3A15 and CYP3A17 were significantly decreased by the AsA deficiency, clearly indicating that the expression of each isozyme within the CYP3A subfamily is differently regulated by AsA. These results support the idea that the transcription of P450 is regulated by AsA in guinea pigs.

Use of a new vitamin C-deficient diet in a depletion/repletion clinical trial

To conduct an inpatient study on the recommended dietary allowance (RDA) for vitamin C, we developed a unique vitamin C-deficient diet using a nutrient database and selective menus. Fourteen different menus were developed offering > 300 items with 0-2.4 mg vitamin C per serving. During the 4-6 mo volunteers were hospitalized, daily dietary vitamin C was restricted to < or = 5.0 mg. The mean daily dietary vitamin C intake was < 3.9 mg for the seven study subjects. With concurrent supplementation, the diet provided > or = 85% of the RDA for 17 essential nutrients. Within 3 wk of admission the diet induced vitamin C deficiency as indicated by plasma concentrations, which decreased from 23 +/- 6.9 to 6.9 +/- 2.0 mumol/L. Daily intake of vitamin C and five other nutrients was determined by nutrient database analyses. Mean energy, protein, the iron were 105-185% of the RDA and total and saturated fat were 32% and 10% of energy, respectively. Weight and nutritionally relevant indexes remained normal. Dietary adherence, calculated by the number of days with < or = 5.0 mg vitamin C per total study days, was 88-98% per repletion dose. Computer analyses of menu selections permitted individual preferences to be met while restricting vitamin C intake to < or = 5.0 mg/d. There were no complications from the diet during the depletion and repletion phase. With this diet, ascorbic acid pharmacokinetics for escalating doses could be determined in healthy volunteers.

METABOLISM OF COLLAGEN IN MAMMALIAN TISSUES

The amino acid composition of collagen is described and the status of knowledge about the synthesis of its unique amino acids, hydroxyproline and hydroxylysine, presented. This is followed by a schematic overview of collagen metabolism. Scurvy and lathyrism, the only two abnormalities of collagen metabolism which can now be reasonably elucidated at a molecular level, are then discussed in some detail. The paper concludes by stressing the importance of recognizing the role of histoarchitecture and of interactions of collagen with other compounds when studying collagen or its metabolism in the whole animal.