Use of chicken eggshell to improve dietary calcium intake in rural sub-Saharan Africa

Undernutrition resulting from inadequate access to high‐quality, nutritious food is a widespread issue in sub‐Saharan Africa impacting the health and survival of mothers and their children. Inadequate dietary intake leads to a deficiency in nutrients including calcium, required for growth and physiological functioning. This study investigated the potential of increasing dietary calcium intake by the addition of heat‐treated ground eggshell to locally prepared food. A mixed methods approach of literature review, Delphi expert survey and focus group discussions with women of childbearing age in rural Tanzania, were used to assess the practicality, safety, and acceptability of consumption of ground eggshell. Chicken eggshell has high calcium content (380 mg of calcium/gram) and bioavailability comparable to calcium carbonate (~39%) with 1 g sufficient to provide one half of a sub‐Saharan African adult female's dietary calcium needs. Salmonella was indicated as the most likely threat to human health through eggshell consumption. Experts agreed that eggshells boiled for 10 min when preparing hard‐boiled eggs with a further 20 min cooking of crushed eggshell in staple foods would eliminate identified egg‐associated pathogens. Five focus groups (n = 46) indicated eggshells were perceived as waste. However, there was an indication of general acceptance of the approach and a willingness to consider the incorporation of ground eggshells into their diets. Development of suitable communication methods are required to convey benefits and safe preparation methods. Ground eggshell could be a highly equitable method of increasing calcium intakes across rural sub‐Saharan Africa where calcium intake is low and village poultry ownership common

Evidence-based policy on dietary calcium and vitamin D

Copyright © 2011 American Society for Bone and Mineral Research.Peer reviewedPostprin

The Role of Calcium in Osteoporosis

Calcium requirements may vary throughout the lifespan. During the growth years and up to age 25 to 30, it is important to maximize dietary intake of calcium to maintain positive calcium balance and achieve peak bone mass, thereby possibly decreasing the risk of fracture when bone is subsequently lost. Calcium intake need not be greater than 800 mg/day during the relatively short period of time between the end of bone building and the onset of bone loss (30 to 40 years). Starting at age 40 to 50, both men and women lose bone slowly, but women lose bone more rapidly around the menopause and for about 10 years after. Intestinal calcium absorption and the ability to adapt to low calcium diets are impaired in many postmenopausal women and elderly persons owing to a suspected functional or absolute decrease in the ability of the kidney to produce 1,25(OH)2D2. The bones then become more and more a source of calcium to maintain critical extracellular fluid calcium levels. Excessive dietary intake of protein and fiber may induce significant negative calcium balance and thus increase dietary calcium requirements. Generally, the strongest risk factors for osteoporosis are uncontrollable (e.g., sex, age, and race) or less controllable (e.g., disease and medications). However, several factors such as diet, physical activity, cigarette smoking, and alcohol use are lifestyle related and can be modified to help reduce the risk of osteoporosis

Experimental Evidence for the Effects of Calcium and Vitamin D on Bone: A Review

Animal models fed low calcium diets demonstrate a negative calcium balance and gross bone loss while the combination of calcium deficiency and oophorectomy enhances overall bone loss. Following oophorectomy the dietary calcium intake required to remain in balance increases some 5 fold, estimated to be approximately 1.3% dietary calcium. In the context of vitamin D and dietary calcium depletion, osteomalacia occurs only when low dietary calcium levels are combined with low vitamin D levels and osteoporosis occurs with either a low level of dietary calcium with adequate vitamin D status or when vitamin D status is low in the presence of adequate dietary calcium intake. Maximum bone architecture and strength is only achieved when an adequate vitamin D status is combined with sufficient dietary calcium to achieve a positive calcium balance. This anabolic effect occurs without a change to intestinal calcium absorption, suggesting dietary calcium and vitamin D have activities in addition to promoting a positive calcium balance. Each of the major bone cell types, osteoblasts, osteoclasts and osteocytes are capable of metabolizing 25 hydroxyvitamin D (25D) to 1,25 dihydroxyvitamin D (1,25D) to elicit biological activities including reduction of bone resorption by osteoclasts and to enhance maturation and mineralization by osteoblasts and osteocytes. Each of these activities is consistent with the actions of adequate circulating levels of 25D observed in vivo

Dietary Acid Load and Bone Turnover During Long-Duration Spaceflight and Bed Rest

Background Bed rest studies document that a lower dietary acid load is associated with lower bone resorption. Objective We tested the effect of dietary acid load on bone metabolism during spaceflight. Design Controlled 4-d diets with a high or low animal proteinto-potassium (APro:K) ratio (High and Low diets, respectively) were given to 17 astronauts before and during spaceflight. Each astronaut had 1 High and 1 Low diet session before flight and 2 High and 2 Low sessions during flight, in addition to a 4-d session around flight day 30 (FD30), when crew members were to consume their typical in-flight intake. At the end of each session, blood and urine samples were collected. Calcium, total protein, energy, and sodium were maintained in each crew member's preflight and in-flight controlled diets. Results Relative to preflight values, N-telopeptide (NTX) and urinary calcium were higher during flight, and bone-specific alkaline phosphatase (BSAP) was higher toward the end of flight. The High and Low diets did not affect NTX, BSAP, or urinary calcium. Dietary sulfur and age were significantly associated with changes in NTX. Dietary sodium and flight day were significantly associated with urinary calcium during flight. The net endogenous acid production (NEAP) estimated from the typical dietary intake at FD30 was associated with loss of bone mineral content in the lumbar spine after the mission. The results were compared with data from a 70-d bed rest study, in which control (but not exercising) subjects APro:K was associated with higher NTX during bed rest. Conclusions Long-term lowering of NEAP by increasing vegetable and fruit intake may protect against changes in loss of bone mineral content during spaceflight when adequate calcium is consumed, particularly if resistive exercise is not being performed. This trial was registered at clinicaltrials.gov as NCT01713634

Urine Calcium But Not Plasma Calcium or Urine Hydroxyproline Is Increased by a Systemic Acidosis in the Dairy Cow

Eight non-lactating, pregnant Holstein-Friesian cows were allocated to two treatments and individually offered diets differing in dietary cation-anion difference. Decreasing the dietary cation-anion difference reduced the urine pH within hours of anionic salt supplementation. Plasma calcium concentration was unaffected by dietary cation-anion difference but urine calcium concentration was significantly increased within 10 days of including anionic salts in the diet. Faecal calcium concentration was significantly reduced, indicating increased calcium absorption. Dietary calcium concentration or dietary cationanion difference did not significantly affect urinary hydroxyproline

The Effect of Treatment of Acidosis on Calcium Balance in Patients with Chronic Azotemic Renal Disease

Small but statistically significant negative calcium balances were found in each of eight studies in seven patients with chronic azotemic renal disease when stable metabolic acidosis was present. Only small quantities of calcium were excreted in the urine, but fecal calcium excretion equaled or exceeded dietary intake. Complete and continuous correction of acidosis by NaHCO3 therapy reduced both urinary and fecal calcium excretion and produced a daily calcium balance indistinguishable from zero. Apparent acid retention was found throughout the studies during acidosis, despite no further reduction of the serum bicarbonate concentration. The negative calcium balances that accompanied acid retention support the suggestion that slow titration of alkaline bone salts provides an additional buffer reservoir in chronic metabolic acidosis. The treatment of metabolic acidosis prevented further calcium losses but did not induce net calcium retention. It is suggested that the normal homeostatic responses of the body to the alterations in ionized calcium and calcium distribution produced by raising the serum bicarbonate might paradoxically retard the repair of skeletal calcium deficits

Status of Dietary Intake of Calcium in Women of Reproductive Age in Delhi, India

Background: Calcium (Ca) plays an important role in bone formation. Attaining optimal bone mass and peak bone densities is essential to prevent osteoporotic fractures in future life. In conditions of Ca deficiency, Ca from the bones maintains the blood levels of Ca leading to its depletion in bones. Calcium depletion leads to poor bone density and a higher risk of osteoporosis particularly in women who have repeated episodes of pregnancy and lactation. Aim & Objective: To assess the dietary intake of calcium. Material Methods: the study was conducted among 200 healthy women of reproductive age group of 20-49 years. Result: The dietary intake of calcium was less than the Recommended Dietary Allowances of 600mg/day. Women from upper socioeconomic class had a higher intake of dietary calcium 435±268 mg/day as compared to women from low socioeconomic class with a dietary intake of 295±163 mg/day. Conclusion: The dietary intake of calcium improved with an increase in socioeconomic class

Trend in dietary calcium intake among elderly in Kuantan, Pahang

Introduction: Dietary calcium intake is important in body system regulation. Inadequate intake among elderly may lead to various health issues such as osteoporosis and hip fracture. In order to counter the problem, this study was carried out to identify dietary calcium intake among elderly in Kuantan, Pahang. Methods: A face to face interviewer-administered session was done individually with seventy-nine (n=79) subjects aged ≥60 years to collect data on sociodemographic background, health status and dietary intake. Diet history method was used to obtain information related to dietary intake and analyzed using Nutritionist Pro Software. P-value was set at p<0.05 as statistically significant. Results: Almost all elderly subjects had dietary calcium intake lower than recommendation, which was 92.4%, and only 7.6% of total elderly met the recommended intake. This study found that the mean dietary calcium intake was 421.7 + 344.3 mg/day which is lower than Recommended Nutrient Intakes (RNI) for Malaysian. Mean calcium intake was significantly lower than RNI in both gender (p<0.001). The difference of calcium intake between male and female elderly was not significant; with mean dietary calcium intake for male and female were 414.2 + 344.3 mg/day and 426.0 + 347.8 mg/day, respectively. From the analysis, dietary calcium intake in elderly from non-dairy sources (228.4 + 149.3 mg) is higher than dairy sources (median (IQR)= 0.0 (326.0) 5mg). Conclusions: In conclusion, inadequate dietary calcium is an issue among elderly people in Kuantan which may lead to several health problems. Hence, appropriate strategies need to be taken in order to ensure optimum nutritional status among this at risk population

What is the relationship between dietary calcium intake and CVD risk factors in a college-age population?

Abstract: Risk factors for cardiovascular disease (CVD) including dyslipidemia and hypertension can develop in adolescence and increase risk of CVD in adulthood. Improved blood pressure and lipid profiles are associated with higher dietary calcium intake in older adults, but limited data exists in young adults. Purpose: Determine the relationship between dietary calcium intake and CVD risk factors in a college-age population. Methods: IRB approval was obtained. Fasting blood samples were collected from 149 college students ages 18-24. Serum total cholesterol (TC), LDL, HDL, and triacylglycerol (TG) concentrations were measured using a LDX Cholestech machine, blood glucose using a Precision Xtra glucometer, and blood pressure (systolic [SBP] and diastolic [DBP]) using an Omron automated sphygmomanometer. Dietary calcium intake was assessed using the Brief Calcium Assessment Tool (BCAT) (1). Correlation between CVD risk factors and dietary calcium was determined. Unpaired t-tests determined differences between sexes. Results: Average daily dietary calcium intake was 804 mg (RDA for 18 year olds: 1300mg, 19-50 year olds: 1000mg). Mean calcium intake was 186 mg lower in females than males (p=0.001). Acceptable TC, LDL, and TG concentrations occurred in 85%, 92%, and 75% of total participants respectively based on guidelines for 20-24 year olds (2). HDL concentrations were normal 75% of participants and SBP and DBP were normal in 84% and 87% of subjects, respectively. Mean HDL was lower in males than in females (p=0.001). Mean SBP was higher in males than females (p=0.000). TGs were positively correlated with dietary calcium intake (r=0.221, p=0.010). Conclusions: Average dietary calcium intake in college students is below recommendations and over half (56%) consumed less than 1000mg and 29% consumed less than 400mg. The majority of participants fell within normal ranges for lab values. Education about meeting dietary calcium recommendations may be warranted in a college-age population. The positive correlation between dietary calcium and TGs was unexpected and may be attributed to the calcium sources and the relatively small sample size