[A nutritional survey in Tibet]

We present the most striking results of a nutritional assessment held in Tibet from May to July 1990, performed at the request of the Health Authorities of the Tibet Autonomous Region. Using a cut-off value which adjusts for the haemoglobin increase with increasing altitude, 40% of the women of reproductive age were considered anaemic. However, the distribution of their haemoglobin values was gaussian with a mean value of 13.6%. Apparently, the Tibetans respond differently to high altitude, compared to other populations living at high altitudes. Goitre remains a problem despite the goitre control program. Rickets, investigated by clinical signs, was prevalent in 9.2% of the children 0 to 6 years old. Rural children were shorter and lighter than urban ones and started to accumulate their deficit earlier.

Current status of nutritional deficiencies in Canadian aboriginal people

Since the Nutrition Canada Survey (1973) there has been clear evidence that Aboriginal people have low intakes of many nutrients such as iron, vitamin D, calcium, folate, vitamin A, and fluoride. Recent surveys suggest that the situation has not changed. Children are most likely to be affected clinically. More than half of Aboriginal children in some subpopulations in Manitoba suffer a period of iron deficiency, which may affect development. Nutritional rickets is still a common problem in Manitoba. We have seen cases of megaloblastic anemia due to folate deficiency. The relationship of the well-described low folate intake in pregnancy and birth defects has received no attention for the Aboriginal population. In a recent survey of Inuit children, dental caries of the primary teeth were present in over 70% of children, with a mean DMF (decayed, missing, and filled) index of 1.8 teeth in children under 2 and 9.5 in children 6 to 8 years. Although clinical vitamin A deficiency is not seen, there is now good evidence that subclinical deficiency increases susceptibility to infections. Although not all Aboriginal populations suffer all of these deficiencies, the problems are sufficiently widespread to suggest this is an urgent problem. It will not be solved simply by education. There must be a political will and a coordinated effort to make a balanced diet available to all at an affordable cost.

Solar ultraviolet B radiation and photoproduction of vitamin D3 in central and southern areas of Argentina

The incidence of nutritional rickets in the southern part of Argentina is 8-12 times higher than in the rest of the country. Winter 25(OH)D serum levels in normal population of southern areas are lower than in central and northern areas. To elucidate these differences, we compared the photoconversion of provitamin D3 (7-DHC) to previtamin D3 in two cities: Ushuaia (latitude 55 degrees S) and Buenos Aires (34 degrees S). Ampules containing 7-DHC were exposed to sunlight one day in the middle of each month either from 10:30 a.m. to 2:30 p.m. or from 8:00 a.m. to 5:00 p.m. The percentages of photoproducts formed were determined by high performance liquid chromatography (HPLC). Previous studies have proved that this is a valid model to assess "in vitro" the photoproduction of vitamin D3 in human skin. Previtamin D3 + vitamin D3 formed in Ushuaia were less (p < 0.02) than those found in Buenos Aires during all seasons: summer, (X +/- SEM) 6.4 +/- 0.8% vs. 13.2 +/- 1.8%; autumn, 1.2 +/- 0.7% vs. 6.3 +/- 1.3%; winter, 0.8 +/- 0.7% vs. 3.6 +/- 0.7%; spring, 3.4 +/- 0.5% vs. 9.1 +/- 1.1%. The photoproducts produced from 10:30 a.m. to 2:30 p.m. were similar for each month and latitude to those formed when the ampules were exposed from 8:00 a.m. to 5:00 p.m. We conclude that in Ushuaia there is a prolonged "vitamin D winter" during which cutaneous synthesis of vitamin D is absent, leading to lower serum values of 25(OH)D and contributing to the higher incidence of rickets.

Nutritional vitamin D deficiency rickets in Sudanese children

Nutritional vitamin D deficiency rickets was established in 41 Sudanese children aged from 3 months to 7 years by clinical, radiological and therapeutic response supported by biochemical investigations. There were 25 boys and 16 girls, of whom 42% were infants of less than 1 year. Forty-seven per cent of rachitic children were underweight. Six infants had early rickets with no bony swellings but had other clinical features and radiological evidence of rickets. One of them, aged 3 months, presented with hypocalcaemic convulsions. Three children had icthyosis. Serum alkaline phosphatase was raised in 75%, hypophosphataemia occurred in 68% and hypocalcaemia in 54% of patients. Anaemia, mostly hypochromic, was detected in 79%. Possible causes were poor socio-economic background, inadequate dietary intake in both mothers and children, prolonged breastfeeding, prematurity, limited sun exposure and type of residence. Nutritional vitamin D deficiency rickets should be looked for in Sudanese children, especially in preterms and in those living in flats.

Prematurity as a predictor of rickets in Shanghai infants

The association between prematurity and the prevalence of rickets was examined among 2,227 infants in Shanghai, China. The prevalence of rickets during subjects' first 18 months of life was 6.8% in boys and 4.6% in girls. Pre-term infants were more likely to have rickets than term (> or = 37 weeks gestation) infants, 9.4% versus 5.2%. Birth weight was inversely related to the prevalence of rickets, 15.8% in the < 2,500 g group, 7.1% in the 2,500-2,999 g group, 4.9% in the 3,000-3,499 g group, and 4.2% in the > or = 3,500 g group. After adjusting for covariates including sex, average family income and birth weight, the odds ratio for rickets in pre-term infants was 1.55 compared with term infants. The inverse relationship between birth weight and rickets remained significant after taking sex, family income and pre-term birth into account. In addition, infants of the lower income families were more likely to have rickets than those of higher income families.

Vegetarian diets and children

The diets and growth of children reared on vegetarian diets are reviewed. Excessive bulk combined with low energy density can be a problem for children aged < or = 5 y and can lead to imparied growth. Diets that have a high content of phytate and other modifiers of mineral absorption are associated with an increased prevalence of rickets and iron-deficiency anemia. Vitamin B-12 deficiency is a real hazard in unsupplemented or unfortified vegan and vegetarian diets. It is suggested that vegans and vegetarians should use oils with a low ratio of linoleic to linolenic acid in view of the recently recognized role of docosahexaenoic acid in visual functioning. If known pitfalls are avoided, the growth and development of children reared on both vegan and vegetarian diets appears normal.

Quantitative requirement for cholecalciferol in the absence of ultraviolet light

Studies were conducted to determine the basic requirement of the bird for cholecalciferol in the absence of ultraviolet light by utilizing filter sleeves on fluorescent lights in the room and brooder. In Experiment 1, some pens were fitted with filter tubes and some lights were turned off. All the birds received a cholecalciferol-deficient diet. Birds with ultraviolet light excluded grew slowly, developed rickets (95%), had low plasma calcium, and low bone ash (27%); whereas birds exposed to the fluorescent light had normal growth and plasma calcium, slightly low bone ash (38%), and some rickets (12%). Experiments 2 and 3 were conducted to determine the amount of cholecalciferol that must be added to the diet under conditions in which ultraviolet light was excluded. In Experiment 2, the highest level of cholecalciferol fed was 400 ICU/kg. This level was not sufficient to permit the chickens to have weight gain or bone ash equal to the birds receiving the ultraviolet light. The birds receiving 400 ICU/kg of diet also had a 77% incidence of rickets compared with 20% for the birds receiving ultraviolet lights. In Experiment 3, when birds received 800 or 1,600 ICU/kg of cholecalciferol in the diet, they grew and were comparable to those receiving ultraviolet light for the criteria measured.

[Health status in cradled children from the city of Chorzow from districts of greatest atmospheric air pollution (morbidity, lead concentration in blood)]

The results are presented of health condition evaluation in 291 cradled children. High morbidity was found, mainly of respiratory tract diseases, and excessive exposure to lead was observed. The acceptable level of lead according to the WHO standards (10 micrograms/dl) was exceeded in 63.9% of the studied children. High per cent (47.6%) of children with lead level over 20 micrograms/dl showed rachitic bone deformities.

Seasonal variations of 25 hydroxyvitamin D and parathyroid hormone in Ushuaia (Argentina), the southernmost city of the world

Serum levels of calcium, phosphorus, alkaline phosphatase, 250HD, 1.25(OH)2D and PTH were studied in a group of 42 children aged 8.5 +/- 1.8 years (X +/- SD) from the city of Ushuaia (latitude 55 degrees S), at both the end of the winter and the end of summer. Calcium, phosphorus, alkaline phosphatase and 1.25(OH)2D serum levels were not different in summer and winter. The levels of serum 25OHD were significantly higher in summer (18.4 +/- 7.3 ng/ml) than in winter (9.8 +/- 3.8 ng/ml P < 0.001). The levels of 25OHD in children with fair or dark skin were similar in winter but were significantly higher in children with fair skin in summer (20.0 +/- 7.2 ng/l vs 15.3 +/- 5.1 ng/ml (P < 0.05). Serum levels of PTH were higher in winter (58.2 +/- 30.5 pg/ml) than in summer (47.9 +/- 28.3 pg/ml) (P < 0.03). The results demonstrate the existence of a population with low serum levels of 25OHD in winter. The higher levels of PTH in winter when serum 25OHD levels are lower could be the cause of the lack of seasonal variation in serum calcium and 1.25(OH)2D levels. Further studies are needed to establish whether these changes besides increasing the incidence of rickets, could also affect the mineral density of the skeleton in the population of this vitamin-D-deficient area.

Studies on iron deficiency anemia, rickets and zinc deficiency and their prevention among Chinese preschool children

The incidence of iron deficiency anemia, rickets, and zinc deficiency is very high in Chinese preschool children and a method for prevention is urgently needed. From our studies, it can be seen that a soft drink powder is a convenient vehicle for the supplementation of iron, zinc, calcium, vitamin D, riboflavin, and ascorbic acid. Table salt is also a good, low-cost carrier for iron and zinc, and cow's milk can only be used for the enrichment of vitamins A and D. In our study the therapeutic dose of iron was lower than 3 mg/kg body weight recommended by the WHO Expert Committee. As ascorbic acid can enhance the absorption of iron in the body, so 300 mg vitamin C was added to 100 g of soft drink powder containing 100 mg of elemental iron. Ten g of powder is not only enough for the prevention of iron deficiency anemia but it can also cure iron deficiency anemia within 3 months. One hundred mg of iron in 100 g of table salt is an adequate level, because an adult or a child taking 10 or 5 g of salt will receive 10 and 5 mg of elemental iron respectively. This dosage is adequate for the prevention of anemia. From our results, 10 mg of zinc daily is enough for the prevention and treatment of zinc deficiency in preschool children. Four hundred IU of vitamin D (from fortified soft drink powder or enriched fresh cow's milk) orally-administered daily, is a good way to prevent rickets in infants and young children.

Trace elements and mineral requirements for very low birth weight infants in rickets of prematurity

To establish mineral and trace element requirements for very low birth it is important to prevent bone mineral disorder. Those infants fed mother's milk only are thought to be at higher risk of this disorder. Both calcium and phosphorus supplementation were thought to be needed to prevent it. Copper and zinc are important as cofactors of major enzymes involved in the synthesis of collagen. These trace elements especially zinc may not be enough for very low birth weight infants fed mother's milk. At present however the relationship between these trace elements and minerals, and bone metabolic disease in preterm infants is not completely clear.

Prospective study of vitamin D supplementation and rickets in China

To determine whether amounts of vitamin D lower than recommended doses are effective in preventing rickets, 256 term infants from two northern and two southern cities in China were studied in a randomized trial of vitamin D supplementation (100, 200, or 400 IU/day) during the first 6 months of life. Cord blood and 6-month blood samples were collected and radiographs were obtained at 3 to 5 days and at 6 months of age. Cord serum 25-hydroxyvitamin D concentrations were lower in the north than in the south (5 vs 14 ng/ml (12.5 vs 35.0 nmol/L); p less than 0.01). Wrist ossification centers were less likely to be present at birth in the northern children than in the southern children (p = 0.009) and were more likely to be present in infants born in the fall who had higher cord serum concentrations of 25-hydroxyvitamin D (p = 0.04). Serum 25-hydroxyvitamin D concentrations were lower in northern children 6 months of age than in southern children (p = 0.005) and were higher with an increasing supplemental dosage of vitamin D (p less than 0.001), particularly in infants in the north. None of the infants had rickets at 6 months of age. Because of the low serum 25-hydroxyvitamin D concentrations, especially among infants in the north, it may be prudent to supplement the diet with vitamin D at a dose of 400 IU/day.

X-linked hypophosphatemic rickets without "rickets"

Wrist and knee radiographs from children with X-linked hypophosphatemic rickets were analyzed and compared with those from normal children and children with established rickets to assess whether radiographically apparent rickets is a consistent abnormality in X-linked hypophosphatemia. The absence or presence of rickets was correctly identified in 94.8% of wrist and knee films from normal and positive controls. In contrast, patients with X-linked hypophosphatemia exhibited rachitic abnormalities in only 5 of 11 wrist and 13 of 15 knee radiographs. As a result, 4 patients within this study group had rickets at the knee and not at the wrist, whereas 5 displayed classic defects at both sites. Perhaps more important, 2 patients, aged 3.8 and 5.2 years, displayed no evidence of rickets in either wrist or knee films, although relatives exhibited demonstrable rachitic abnormalities. Our data indicate that radiographically detectable rickets is a variable abnormality of X-linked hypophosphatemia and does not provide an unambiguous index for the diagnosis of this disease.

Severe rickets in a children's hospital in Addis Ababa

A retrospective, case-controlled study of rachitic patients admitted to Ethio-Swedish Children's Hospital (ESCH), Addis Ababa, Ethiopia, over a ten-year period (1979-1988) is presented. Clinical records of 131 patients with clinical and radiological evidence of rickets and an equal number of randomly selected, age and sex matched controls with no rickets were analysed. Rickets was found to be more common in males (2:1) and at 6 to 18 months of age (79%). Associated findings were infectious diseases (90%), protein-energy malnutrition (75%), anaemia (39%), and congestive heart failure (16). Mortality was much higher in rachitic patients. The admission rates show a progressive increase over the study period. The need for early diagnosis and treatment, continued nutrition and health education, and further study to elucidate the relation between protein-energy malnutrition (PEM) and rickets is suggested.

Familial hypophosphataemic rickets: experience with 24 children from Kuwait

Between 1982 and 1988, familial hypophosphataemic rickets (FHR) was diagnosed in 24 children, in nine during screening of the families of index patients. The average annual incidence was 0.2/1000 live births. There were 16 boys and 8 girls in 10 families, of which nine had more than one affected child. Their ages at the onset of the disease ranged between 10 months and 14 years (mean 6.9 yrs). Growth retardation and bowing of the legs were the most prominent features, observed in all index patients and in four of the patients diagnosed by screening. Treatment with 1 alpha-hydroxyvitamin D3 and phosphates was associated with acceleration of growth in all children, healing of rickets in 21, and normalization of the serum phosphate in 22. Two children with late diagnosis are now older than 16 years with a final height below the 3rd centile. Three more pubertal children are also shorter than the 3rd centile. In areas where nutritional rickets is common, FHR is likely to be missed and the treatment delayed with grave consequences; in particular, growth retardation and bone deformity.

Vitamin-D-deficiency rickets in Kuwait: the prevalence of a preventable disease

Two hundred and fifty children with clinical, biochemical and radiological evidence of vitamin-D-deficiency rickets were studied over a period of 5 years. Their ages ranged from 1 month to 2 years. Breastfed infants formed 63% of total cases. Intramuscular therapy with vitamin D in a dose of 600,000 IU, deep intramuscular, proved to be safe and effective. In contrast, oral vitamin D did not provide such satisfactory results, presumably owing to poor patient/parental compliance. This report reveals that vitamin-D-deficieny rickets is common in Kuwait in spite of abundant sunlight all through the year because children are wrapped up and kept indoors. Insufficient intake of vitamin D is another important factor in the pathogenesis of vitamin-D-deficiency rickets in Kuwait.

Rickets associated with vitamin D deficiency in young sheep

An outbreak of rickets in sheep under a year old (hoggs) appeared clinically as stiffness and rotation of the carpal joints. Histological studies confirmed the diagnosis and biochemical analyses of blood demonstrated a primary vitamin D deficiency.

The importance of limited exposure to ultraviolet radiation and dietary factors in the aetiology of Asian rickets: a risk-factor model

Regional variation in the prevalence of Asian rickets was examined in Coventry, Bradford and Glasgow. Records of 152 weeks of daylight outdoor exposure were obtained from 104 Glasgow Asian children, 53 of whom had been treated for rickets. Records of seven-day weighed dietary intake were obtained from 84 Asian children, 43 of whom had been treated for rickets. There was a marked north-south gradient in the prevalence of Asian rickets. In all cases of severe rickets with deformity the child was vegetarian. Severe rickets was associated with lower intake of meat, higher intake of chapati and lower daylight outdoor exposure values than in normal children. Multivariate analysis employing a combination of these variables provided good separation between rachitic and normal groups. A risk-factor model is proposed which suggests that regional variation in the prevalence of rickets among Asian communities in Britain is mainly determined by the effects of latitude and the nature of the urban environment on available ultraviolet radiation. Where UV radiation is restricted, individual propensity to rickets within a given Asian community is mainly determined by dietary factors.

High levels of childhood rickets in rural North Yemen

Despite a warm sunny climate, rickets is extremely common in children living in an isolated mountainous area of North Yemen. In a small township the overall prevalence amongst children under five years attending for vaccination was 27%. The condition was most common at the end of the first year and had disappeared by the fifth year. Marasmus was commonly associated with rickets. Children from the rural villages outside the township had significantly lower rates of rickets. Several factors may contribute to the very high rates of rickets in rural Yemen. However, lack of exposure to sunlight as a consequence of particular cultural practices is likely to be the most important. The major social and behavioural factors which restrict the young child access to sunlight are outlined, and possible remedies discussed.