The effects of vitamin D supplementation on muscle strength and mobility in postmenopausal women: a systematic review and meta-analysis of randomised controlled trials.

BACKGROUND: The results obtained from previous trials regarding the effects of vitamin D supplementation on muscle strength and mobility in postmenopausal women have been inconsistent. This systematic review and meta-analysis of randomised controlled trials (RCTs) aimed to investigate the effect of vitamin D supplementation on muscle strength and mobility in postmenopausal women. METHODS: A comprehensive search on EMBASE, PubMed, MEDLINE and SCOPUS was performed to identify relevant articles published up to 28 March 2019. RCTs published in English measuring the effect of all forms and doses of vitamin D supplementation with or without calcium on muscle strength and mobility outcomes in postmenopausal women were included. RESULTS: In total, 29 eligible studies were included in the systematic review. The pooled findings using a random effects model showed that vitamin D supplementation insignificantly increased hand grip strength (HGS) as the measurement of muscle strength (MD = 0.656; 95% confidence interval = -0.037 to 1.350, P = 0.06). However, it did not affect timed-up-and-go (TUG) as the measurement of mobility (MD = 0.118; 95% confidence interval = -0.655 to 0.892, P = 0.76). The subgroup analyses showed that vitamin D supplementation improved HGS with respect to dosages >1000 IU day-1 (P = 0.016), a treatment duration of 3 months (P Ë‚ 0.001) and subjects with baseline vitamin D <30 ng mL-1 (P = 0.033). CONCLUSIONS: The present review demonstrates that vitamin D supplementation resulted in small but nonsignificant improvements in muscle strength compared to control in postmenopausal women. No significant effect was observed in mobility after vitamin D administration.

An expert consensus-based guideline for the integrative anthroposophic treatment of acute gastroenteritis in children.

OBJECTIVES: Acute gastroenteritis is one of the major causes of hospital admission in childhood. The primary objective of the treatment is rehydration, but conventional drug therapies are limited. Therefore, several pediatricians supplement conventional treatment with complementary and alternative therapies. In the two German departments for pediatric integrative medicine, children suffering from an acute gastroenteritis are treated with supportive therapy based on anthroposophic medicine. However, up to now scientifically validated guidelines for these therapies are lacking. DESIGN: We consulted an expert pool of 50 physicians with expertise in anthroposophic medicine as well as pediatrics and invited them to participate in an online-based Delphi process. Results were analyzed by means of qualitative content analysis with two independent raters using MAXQDA. Using four rounds of questioning, a consensus-based guideline was developed. RESULTS: A strong consensus (>90%) or consensus (>75-90%) was achieved for 14 of 16 subsections. The guideline describes disease characteristics, the most useful diagnostics, drug as well as non-drug treatment recommendations and advises for a good physician-patient interaction. CONCLUSION: The guideline will help clinicians, as well as family doctors, in their daily routine and make anthroposophic medicine more tangible for parents and health insurance companies.

Effects of Soy Phytoestrogens and New Zealand Functional Foods on Bone Health.

New Zealand is a rich source of food components that may have bioactivity on bone. Docosahexaenoic acid (DHA) from fish oil has been shown to maintain bone in ovariectomised (OVX) rats. Kiwifruit, a source of fibre and carotenoids, may also affect bone via a prebiotic as well as direct cell-based mechanisms. We aimed to 1) ascertain the effects of DHA on two cell models, including interactions with soy isoflavones; 2) and investigate the specific effects of carotenoids from kiwifruit as well as whole kiwifruit in cell-based and rodent models as well as in a human study. RAW 264.7 mouse monocytes or mouse bone marrow was used to generate osteoclasts (OC). Cells were exposed to the agents between 5 and 21 d and formation and activity of OC measured, including molecular markers. DHA inhibited OC formation in both cell models, including expression of cathepsin K, NFATc1 as well as actin ring formation. Combination with isoflavones enhanced these effects. In OVX rats and mice fed with kiwifruit for 8 wk, green kiwifruit reduced the rate of bone loss after OVX, and in mice it reduced C-telopeptide of Type 1 collagen (CTX) levels and RANKL expression while in menopausal women, green kiwifruit affected blood lipids and bone markers positively.

High-calcium, vitamin D fortified milk is effective in improving bone turnover markers and vitamin D status in healthy postmenopausal Chinese women.

BACKGROUND/OBJECTIVES: Risk for developing osteoporosis increases in Asia. The purpose of the study was to evaluate the impact of a high-calcium vitamin D fortified milk (HCM) intervention on parathyroid hormone (PTH) levels, vitamin D status and markers of bone turnover in postmenopausal Chinese women. SUBJECTS/METHODS: Sixty three women (>55 years) were assigned to receive two servings of either a calcium/vitamin D fortified milk or a control drink for 12 weeks. PTH, serum 25 (OH)D levels, C-telopeptide of type I collagen (CTX) levels and procollagen type I N-terminal propeptide (PINP) were measured at baseline, 2, 8 and 12 weeks of supplementation. RESULTS: Daily calcium intake at baseline ranged between 260 and 482 mg for the HCM, and 252 and 692 mg for the control group. HCM improved serum 25 (OH)D levels significantly (33.13-39.49 nmol/l), while remaining similar in the control group (29.27-28.21 nmol/l). The difference between the groups were significant at week 2, 8 and 12. The percentage change in PTH levels in the HCM group was significant from week 2 onwards compared to the control drink (P<0.017, P<0.05 and P<0.001 at weeks 2, 8 and 12, respectively). Plasma CTX of the HCM group reduced by 25% between weeks 0 and 2, remaining significantly lower and at similar levels up to week 12. The difference between the HCM and control group for PINP reached significance at weeks 8 (P=0.011) and 12 (P=0.003). CONCLUSIONS: The HCM intervention significantly improved vitamin D status and reduced bone turnover over 12 weeks in postmenopausal Chinese women.

[On general practitioners' care of patients with asthma]. / HausärztlicheVersorgung von Patienten mit Asthma.

UNLABELLED: This review offers readers new aspects for the guideline-compliant care of asthma patients. Here, attention is focused on illustrating the bottlenecks in the administration of good and practicable therapeutic care and listing these as "major challenges for GPs". The interdisciplinary team of authors - consisting of three hospital-based pulmonologists, one pulmonologist in private practice, one internist in general practice, one pharmacist and one health economist discussed aspects of asthma therapy relevant in clinical practice. RESULTS AND CONCLUSIONS: Practicable results for the reader included an asthma pentagram, a graphic depicting the links and interactions between diagnosis, symptom management, communication, application and costs. From this emerged a consensus on four recommendations that can help GPs improve their care of their patients: (1) Whenever possible, have a specialist verifythe diagnosis. (2) Practice inhalation techniques with the patient and check up on their technique at regular intervals. (3) Monitor and fine-tune the therapeutic goals set down together with the patient. (4) Clearly define the (patient's) responsibilities and who is organizing care (communication between GP-specialist-patient-pharmacist-family members).

Modification of Mo-Si alloy microstructure by small additions of Zr.

Molybdenum and its alloys are potential materials for high-temperature applications. However, molybdenum is susceptible to embrittlement because of oxygen segregation at the grain boundaries. In order to alleviate the embrittlement small amounts of zirconium were alloyed to a solid solution of Mo-1.5Si alloy. Two Mo-based alloys, namely Mo-1.5Si and Mo-1.5Si-1Zr, were investigated by the complementary high-resolution methods transmission electron microscopy and atom probe tomography. The Mo-1.5Si alloy shows a polycrystalline structure with two silicon-rich intermetallic phases Mo(5)Si(3) and Mo(3)Si located at the grain boundaries and within the grains. In addition, small clusters with up to 10 at% Si were found within the molybdenum solid solution. Addition of a small amount of zirconium to Mo-1.5Si leads to the formation of two intermetallic phases Mo(2)Zr and MoZr(2), which are located at the grain boundaries as well as within the interior of the grain. Transmission electron microscopy shows that small spherical Mo-Zr-rich precipitates (<10nm) decorate the grain boundaries. The stoichiometry of the small precipitates was identified as Mo(2)Zr by atom probe tomography. No Si-enriched small precipitates were detected in the Mo-1.5Si-1Zr alloy. It is concluded that the presence of zirconium hinders their formation.

Long-chain polyunsaturated fatty acids: selected mechanisms of action on bone.

Evidence presented over the past 20 years has shown that long-chain polyunsaturated fatty acids (LCPUFAs), especially the n-3 fatty acids such as eicospentaenoic acid (EPA) and docosahexaenoic acid (DHA) are beneficial for bone health. Some studies in humans indicate that LCPUFAs can increase bone formation, affect peak bone mass in adolescents and reduce bone loss as measured using bone mineral densitometry. The cellular mechanisms of action of the LCPUFAs, however, are complex and involve modulation of fatty acid metabolites such as prostaglandins, resolvins and protectins, several signalling pathways, cytokines and growth factors. LCPUFAs affect receptor activator of nuclear factor κß (RANK), a receptor found on the osteoclast, the cell causing bone resorption, which controls osteoclast formation. Lipoxygenase (LOX) generated lipid mediators (resolvins, lipoxins, protectins and docosanoids) have both anti-inflammatory and pro-resolving activities. Both resolvins and lipoxins inhibit inflammation-induced bone resorption. Arachidonic acid significantly upregulates inducible NO synthase (iNOS) mRNA expression in human osteoblast-like cells, thereby possibly enhancing osteoclastic activity. The protective effect of EPA on osteoblastogenesis could be mediated by the biphasic cross-talk between PGE(2) and NO production involving COX-2 and iNOS pathways. Other mediators of osteoblast maturation include PPARα ligands such as linoleic acid and possibly DHA in association with bone morphogenic proteins. Since DHA is a weaker ligand for PPARγ, more uncommitted mesenchymal stem cells are thought to differentiate into osteoblasts rather than adipocytes. This review addresses selected cellular mechanisms that may explain the beneficial effects of the LCPUFAs on bone.

Vitamin D supplementation suppresses age-induced bone turnover in older women who are vitamin D deficient.

There is a lack of evidence that improving vitamin D status, without changing calcium intake, has a positive effect on bone turnover as indicated by bone marker changes. The objective was to measure the effect of vitamin D supplementation, in vitamin D deficient women (25(OH)D concentration<50 nmol/L), on osteocalcin (OC) and C-telopeptide (CTX). The study design was a randomised controlled intervention administering 4000 IU vitamin D3 or placebo daily for 6 months to South Asian women, aged>20 years. Subjects were stratified by age and menopausal status. Median (25th, 75th percentile) serum 25(OH)D increased significantly from 21 (11, 40) to 75 (55, 84) nmol/L with supplementation. In women>49 years or postmenopausal (n=26), who were not supplemented (n=13), CTX and OC levels increased (P=0.001, P=0.004 respectively), indicating an increased rate of bone turnover. With supplementation CTX decreased (P=0.012) and there was no significant change in OC. In women who were under 49 years and premenopausal (n=55; 29 supplemented), there was no significant response to supplementation in either CTX or OC. We conclude that correcting vitamin D deficiency in older women suppresses the age-induced increase in bone turnover and reduces bone resorption which would normally be exacerbated in conditions of low serum 25(OH)D.

Specific effects of gamma-linolenic, eicosapentaenoic, and docosahexaenoic ethyl esters on bone post-ovariectomy in rats.

Long chain polyunsaturated fatty acids (LCPUFAs) are involved in the regulation of bone metabolism. Increased dietary consumption of n-3, and possibly some n-6, LCPUFAs may limit postmenopausal bone loss. The aim of this study was to determine the effects on bone of specific fatty acids within the n-3 and n-6 LCPUFA families in ovariectomized (OVX) rats. Rats were OVX or sham-operated and fed either a control diet (OVX and sham) or a diet supplemented with 0.5 g/kg body weight/day of gamma-linolenic (GLA), eicosapentaenoic (EPA), docosahexaenoic (DHA) ethyl esters or a mixture of all three (MIX) for 16 weeks. Bone mineral content (BMC), area, and density and plasma concentrations of insulin-like growth factor-I, vitamin D, selected biochemical markers of bone metabolism, and parathyroid hormone (PTH) were determined. The OVX-induced decrease in lumbar spine BMC was significantly attenuated by DHA but not by EPA or GLA supplementation or supplementation with a mixture of all three LCPUFAs. Endosteal circumferences of tibiae were significantly greater in DHA and EPA compared to OVX. Plasma C-terminal telopeptide of type I collagen and osteocalcin concentrations were not significantly different in the DHA group compared to OVX. Femur BMC decreased by a significantly greater amount in GLA than OVX, and final plasma PTH concentrations were significantly higher in GLA compared to all other groups. In conclusion, DHA ameliorated OVX-induced bone mineral loss. GLA exacerbated post-OVX bone mineral loss, possibly as a result of PTH-induced bone catabolism.

Effect of arachidonic acid on duodenal enterocyte ATPases.

Duodenal ion transport processes are supported by ATPase enzymes in basolateral membranes of the enterocyte. In vivo studies have shown that long term n-6 poly-unsaturated fatty acid (PUFA) supplementation in rats causes increases in intestinal Ca absorption, coupled with a higher total calcium balance and bone calcium content. The present in vitro study was undertaken to test the effect of arachidonic acid (AA), a highly unsaturated (and thus physiologically potent) member of the n-6 PUFA family, on ATPases in enterocyte basolateral membranes isolated with a sorbitol density gradient procedure. This paper presents results which show that AA inhibits Na+,K+-ATPase in a dose-dependent manner (-67% of basal activity at a concentration of 30 microg/ml, P < 0.005) but that this effect is not mediated by protein kinase C, as shown by the use of the protein kinase C blocker calphostin (0.5 microM). Indomethacin (IDM) at 0.1 mM, a cyclo-oxygenase blocker, could also not reverse the inhibitory effect of AA on Na+,K+-ATPase. Ca2+-ATPase, on the other hand, is not affected significantly (-10%, P > 0.05) by arachidonic acid at 30 microg/ml.

Modulation of intestinal vitamin D receptor availability and calcium ATPase activity by essential fatty acids.

The physiological mechanisms by which essential fatty acids (EFAs) affect calcium (Ca(2+)) retention is not clear, but suggestions have included changes in membrane fluidity, receptor modulation and induction of second messengers. The vitamin D receptor (VDR) is essential for the functioning of 1,25(OH)(2)D(3)which increases Ca(2+)absorption. Activity of the intestinal basolateral membrane (BLM) Ca(2+)ATPase correlates with the degree of Ca(2+)absorption. Therefore, changes in ATPase activity and VDR availability due to EFAs may influence calcium retention. We have investigated the effect of long-term dietary supplementation with EFAs on Ca(2+)ATPase activity (measured colourimetrically) and VDR availability (measured with the ELISA technique) after the loss of oestrogen induced by ovariectomy (OVX) in female Sprague Dawley rats. Control animals underwent anaesthesia and a surgical procedure but the ovaries were left intact (sham). Ca(2+)ATPase activity was significantly lower in OVX animals than in the intact animals (P<0.05) and following supplementation with EFAs, was significantly higher than in sham controls (P<0.05). A higher number of VDR was measured after OVX and declined due to EFA supplementation; these differences in activity of the ATPase and number of receptors could be ascribed to membrane changes due to EFA supplementation, feedback control by serum calcium or the direct influence of the EFAs.

An overview of EPA regulation of the safe disposal of transuranic waste at the Waste Isolation Pilot Plant.

In March of 1999, the Waste Isolation Pilot Plant (WIPP) in southeast New Mexico, the world's first deep geological repository for radioactive materials, began receiving defense-related transuranic waste. The WIPP was designed and constructed by the U.S. Department of Energy, but critical to its opening was certification by the U.S. Environmental Protection Agency that the repository complies with the radioactive waste disposal regulations set forth as environmental radiation protection standards (40 CFR Part 191) and compliance criteria (40 CFR Part 194). This paper provides a summary of the regulatory process, including the Environmental Protection Agency's waste containment, groundwater protection, and individual dose regulations for the WIPP; the Department of Energy's performance assessment and the other parts of its compliance certification application; and the Environmental Protection Agency's review and analysis of the compliance certification application and related documentation.

Effect of iron-, iodine-, and beta-carotene-fortified biscuits on the micronutrient status of primary school children: a randomized controlled trial.

BACKGROUND: Deficiencies of iron, iodine, and vitamin A are prevalent worldwide and can affect the mental development and learning ability of schoolchildren. OBJECTIVE: The aim of this study was to determine the effect of micronutrient-fortified biscuits on the micronutrient status of primary school children. DESIGN: Micronutrient status was assessed in 115 children aged 6-11 y before and after consumption of biscuits (fortified with iron, iodine, and beta-carotene) for 43 wk over a 12-mo period and was compared with that in a control group (n = 113) who consumed nonfortified biscuits. Cognitive function, growth, and morbidity were assessed as secondary outcomes. RESULTS: There was a significant between-group treatment effect on serum retinol, serum ferritin, serum iron, transferrin saturation, and urinary iodine (P <0.0001) and in hemoglobin and hematocrit (P <0.05). The prevalence of low serum retinol concentrations (<0.70 micromol/L) decreased from 39.1% to 12.2%, of low serum ferritin concentrations (<20 microg/L) from 27.8% to 13.9%, of anemia (hemoglobin <120 g/L) from 29.6% to 15.6%, and of low urinary iodine concentrations (<100 microg/L) from 97.5% to 5.4%. There was a significant between-group treatment effect (P <0.05) in cognitive function with the digit span forward task (short-term memory). Fewer school days were missed in the intervention than in the control group because of respiratory- (P = 0.097) and diarrhea-related (P = 0.013) illnesses. The intervention had no effect on anthropometric status [corrected]. CONCLUSIONS: Fortified biscuits resulted in a significant improvement in the micronutrient status of primary school children from a poor rural community and also appeared to have a favorable effect on morbidity and cognitive function [corrected].

Oestrogen and essential fatty acid supplementation corrects bone loss due to ovariectomy in the female Sprague Dawley rat.

Essential fatty acid deficient animals develop osteoporosis. Eicosapentaenoic acid and gamma-linoleic acid have been reported to have positive effects on bone metabolism in both the growing male rat and the ovariectomized (OVX) female rat. These effects have been further investigated using a novel gamma-linolenic/eicosapentaenoic acid diester together with an oestrogen implant in the ovariectomized, female Sprague Dawley rat. Rats were sham-operated or ovariectomized at age 11 weeks. Two groups of OVX rats received an oestrogen implant at ovariectomy. Animals received fatty acids, linoleic acid (control) or a diester with gamma-linolenic acid and eicosapentaenoic acid as part of a semi-synthetic diet. Bone calcium content and excretion of deoxypyridinolines as marker of bone degradation were measured at 14 weeks. Oestrogen, as well as diester alone, increased calcium/femur to sham levels. Oestrogen plus diester potentiated the effect of oestrogen on bone calcium (P < 0.05 vs OVX). At the same time, oestrogen alone and the combination of oestrogen plus diester significantly reduced (P < 0.05 vs OVX) urinary deoxypyridinoline and hydroxyproline excretion. Again, the diester potentiated the effect of oestrogen. The effects of the diester alone, together with the potentiated effects of oestrogen by the essential fatty acids on osteoporosis, are novel findings.

Ectopic calcification of rat aortas and kidneys is reduced with n-3 fatty acid supplementation.

Supplementation with essential fatty acids has been shown to prevent the experimentally induced ectopic calcification of the kidneys known as nephrocalcinosis. Male Sprague-Dawley rats were fed a semi-synthetic diet supplemented with different essential fatty acids while being injected for a period of 10 days with calcium glubionate. After 3 weeks their kidneys and aorta were removed and the respective calcium content measured compared to the control, saline injected animals. Lipoic acid-EPA, fish oil (EPA rich) as well as the EPA monoester reduced the calcium concentration of both the kidneys and the aorta towards control values. Lipoic-EPA was the best absorbed of the three compounds and its combination of anti-oxidant together with EPA lowered the calcium content of both the aortas and the kidneys.

Calcium, gamma-linolenic acid and eicosapentaenoic acid supplementation in senile osteoporosis.

Recent animal work suggests that gamma-linolenic acid (GLA) and eicosapentaenoic acid (EPA) enhance calcium absorption, reduce excretion and increase calcium deposition in bone. A pilot study was set up to test the interactions between calcium and GLA + EPA in humans. Sixty-five women (mean age 79.5), taking a background diet low in calcium, were randomly assigned to GLA + EPA or coconut oil placebo capsules; in addition, all received 600 mg/day calcium as the carbonate. Markers of bone formation/degradation and bone mineral density (BMD) were measured at baseline, 6, 12 and 18 months. Twenty-one patients were continued on treatment for a second period of 18 months, after which BMD (36 months) was measured. At 18 months, osteocalcin and deoxypyridinoline levels fell significantly in both groups, indicating a decrease in bone turnover, whereas bone specific alkaline phosphatase rose indicating beneficial effects of calcium given to all the patients. Lumbar and femoral BMD, in contrast, showed different effects in the two groups. Over the first 18 months, lumbar spine density remained the same in the treatment group, but decreased 3.2% in the placebo group. Femoral bone density increased 1.3% in the treatment group, but decreased 2.1% in the placebo group. During the second period of 18 months with all patients now on active treatment, lumbar spine density increased 3.1% in patients who remained on active treatment, and 2.3% in patients who switched from placebo to active treatment; femoral BMD in the latter group showed an increase of 4.7%. This pilot controlled study suggests that GLA and EPA have beneficial effects on bone in this group of elderly patients, and that they are safe to administer for prolonged periods of time.

Plasma and red blood cell total phospholipid fatty acid status of nonpregnant female Vervet monkeys (Cercopithecus aethiops) on a high carbohydrate maintenance diet.

Nonhuman primates are of interest as models of human physiology to study the effect of multiple pregnancies on birth weight. Reference plasma and red blood cell (RBC) total phospholipids fatty acids were established in nonpregnant breeding female Vervet monkeys. Twenty-three clinically healthy nonpregnant Vervet monkeys (Cercopithecus aethiops), contained in a controlled closed environment and consuming a high carbohydrate diet (68 E%) that contained 20 E% fat and 12 E% protein were sampled for blood during a cross-sectional study. A low intake of omega3 fatty acids was reflected by a high omega6/omega3 ratio (66:1) of the diet. Inverse relations were seen between plasma and RBC total phospholipid fatty acids, 18:2omega6, 20:3omega6, and 20:4omega6, which suggested selective incorporation in membranes. Low levels of 20:5omega3 and 22:6omega3 of plasma and RBC total phospholipids render Vervet monkeys as ideal subjects to study the effect of omega3 fatty acid supplementation on pregnancy outcomes.

Thresholds and kinetics of fatty acid replacement in different cellular compartments in rat liver as a function of dietary n-6/n-3 fatty acid content.

The kinetics of fatty acid (FA) replacement in different membrane compartments in the rat liver were investigated using diets with varying n-6/n-3 FA ratios. Rats at different stages of growth, i.e. after weaning and at 150 g body weight, were either fed a modified AIN 76A diet containing sunflower oil as fat source or the same diet containing sunflower oil and fish oil to achieve n-6/n-3 FA ratios of 12:1 and 6:1 (diets A and B, respectively). In the adult rats, fed diet A for 8 weeks, C18:2n-6 increased significantly at week 2 in the phosphatidylcholine (PC) fraction of the plasma membranes, microsomes and plasma but not in phosphatidylethanolamine (PE), C20:3n-6 increased significantly at week 2 in the plasma membrane and microsomal PC, but did only increased in PE of both compartments by week 8. C20:4n-6 and the n-3 FAs significantly decreased and increased, respectively, at week 2 in PC and PE of both membrane compartments and plasma PC. The experimental diets led to a change in the plasma membrane fluidity but not in the microsomes. The FA changes in the weaned rats followed a similar pattern as in the adult rats although the changes were greater, depending on the phospholipid fraction and specific FA. The decrease in C20:4n-6 was significantly greater in the microsomal PC and PE and plasma PC but not in the plasma membrane PC and PE. The n-3 FAs increased significantly above the adult levels in the plasma membrane PC and PE respectively but not in the microsomal phospholipid fractions. A plateau for maximal n-3 and n-6 FA incorporation was achieved in the adult rats fed diet A in the microsomes after 2 weeks with no further alterations occurring with diet B. In the plasma PC and plasma membranes most of the n-3 FAs achieved a threshold incorporation after 2 weeks on diet A, except for C22:6n-3 in the plasma membranal PE and certain n-6 FAs in the plasma membrane PC and PE. The present data shows that differences exist in the kinetics of FA incorporation and replacement depending on the specific phospholipid fraction, membrane compartment, age and to a certain extent the dietary n-6/n-3 FA ratio.

Response to an iron fortification programme in relation to vitamin A status in 6-12-year-old school children.

Plasma retinol and indices of iron status were measured in 148 school children (6-12 years) receiving a soup fortified with iron and vitamin C for a period of 15 weeks. The most significant change in serum iron (P = 0.0005) and transferrin saturation (P = 0.0002) was seen in subjects with plasma retinol > or = 40 micrograms/dl, while subjects with plasma retinol < 20 micrograms/dl showed no response. Serum ferritin improved most in the retinol categories < 40 micrograms/dl, suggesting that the absorption of iron was not impaired by marginal vitamin A status, but that it was rather the mobilisation of iron from stores that was affected. Changes in vitamin A status correlated positively and significantly with changes in serum iron (r = 0.37; P = 0.0001) transferrin saturation (r = 0.27; P = 0.004) and haemoglobin (r = 0.21; P = 0.03), but negatively with serum ferritin (r = -0.28; P = 0.003). The presence of marginal vitamin A deficiency in a community may limit the effectiveness of an iron intervention programme and vitamin A status should therefore also be considered when such programmes are planned.

Correlation between essential fatty acids and parameters of bone formation and degradation.

There are two types of essential fatty acids (EFAs), the n-6 derived from linoleic acid (LA) and the n-3, derived from alpha-linolenic acid (ALA). Most of the functions of the EFAs require the conversion of LA and ALA to their metabolites including, gammalinolenic (GLA), dihomogammalinolenic (DGLA), arachidonic (AA) (n-6) and eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids (n-3). Supplementing specific GLA:EPA ratios has effects on bone formation and degradation. A study was designed to investigate the effect of various dietary ratios of n-6:n-3 on calcium homeostasis. Female Sprague Dawley rats were ovariectomised (OVX) at age =11 weeks, and were supplemented from age 12 weeks for six weeks with different ratios (9:1; 3:1; 1:3; 1:9) of GLA:EPA. Bone parameters and red blood cell (RBC) fatty acid profiles were measured at age=18 weeks. RBC GLA and DGLA increased in groups 9:1 and 3:1(p<0.05). EPA and DGLA increased in 1:3 and 1:9 while AA decreased (p<0.05). Correlations were calculated between bone calcium, deoxypyridinoline (Dpyd) and specific fatty acids. DGLA was positively correlated with femur calcium and negatively with Dpyd excretion while DHA and EPA were correlated with femur calcium.