Calcium revisited, part III: effect of dietary calcium on BMD and fracture risk

Optimized Box-Behnken Design Combined Response Surface Methodology to Determine Calcium and Iron Contents Using Visible, Atomic Emission and Atomic Absorption Spectrophotometry in Vegetables and Wastewater Samples

BACKGROUND

Calcium and iron are crucial essential minerals. Iron is mainly responsible for transporting oxygen in the body and the immune system. In comparison, calcium's primary function is in human bones and teeth. Due to that, it is vital to quantify the amount in vegetables.

OBJECTIVE

Optimization and validation of three analytical procedures, visible, atomic emission spectrophotometry (AES), and atomic absorption spectrophotometry (AAS), were developed to determine calcium and iron in vegetables and wastewater samples using response surface methodology (RSM) via Box-Behnken design (BBD). The design helps to reduce experiment trials with selected variables to find a correlation between them and their respective dependent variables.

METHODS

Method I was developed to quantify calcium in vegetables mixed with concentrated 3M HNO3 and heated to reflux as per the BBD. Then it was cooled, filtered, and completed with 3M HNO3 to be carried out utilizing AES and AAS. For method II, vegetables were mixed with nitric acid and sulfuric acid solution with an optimized 5M KSCN solution, which was computed using the AAS and visible spectrophotometry.

RESULTS

First, percentage of water content was calculated for all vegetables, higher in malabar spinach and lower in peas. The calcium and iron contents were present within 0.59-2.68 mg and 35.8-211.5 mg, respectively, in 100 g of vegetables. The results showed a higher amount of iron was available in spinach and a lower amount in okra. In contrast, the highest calcium amount was present in broccoli and the lowest amount was in peas. The calcium and iron content were between 0.015-137.25 and 0.01-147.85 µg/mL in the wastewater samples.

CONCLUSIONS

These methods can help to determine the amount of calcium and iron for the quality control samples in research and development, food, and the environmental industry.

HIGHLIGHTS

Three validated analytical techniques quantify calcium and iron in vegetables and wastewater samples. The RSM-BBD optimized the method and determined its crucial factors.

Placing a Well-Designed Vegan Diet for Slovenes

Interest in vegan diets has increased globally as well as in Slovenia. The quantity of new scientific data requires a thorough synthesis of new findings and considerations about the current reserved position of the vegan diet in Slovenia. There is frequently confusion about the benefits of vegetarian diets that are often uncritically passed on to vegan diets and vice versa. This narrative review aims to serve as a framework for a well-designed vegan diet. We present advice on how to maximize the benefits and minimize the risks associated with the vegan diet and lifestyle. We highlight the proper terminology, present the health effects of a vegan diet and emphasize the nutrients of concern. In addition, we provide guidance for implementing a well-designed vegan diet in daily life. We conducted a PubMed search, up to November 2021, for studies on key nutrients (proteins, vitamin B12, vitamin D, omega-3 long chain polyunsaturated fatty acids (eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)), calcium, iron, zinc, iodine and selenium) in vegan diets. Given the limited amount of scientific evidence, we focus primarily on the general adult population. A well-designed vegan diet that includes a wide variety of plant foods and supplementation of vitamin B12, vitamin D in the winter months and potentially EPA/DHA is safe and nutritionally adequate. It has the potential to maintain and/or to improve health. For physically active adult populations, athletes or individuals with fast-paced lifestyles, there is room for further appropriate supplementation of a conventional vegan diet according to individuals' health status, needs and goals without compromising their health. A healthy vegan lifestyle, as included in government guidelines for a healthy lifestyle, includes regular physical activity, avoidance of smoking, restriction of alcohol and appropriate sleep hygiene.

Milk consumption, dietary calcium intake and nutrient patterns from adolescence to early adulthood and its effect on bone mass: the 1993 Pelotas (Brazil) birth cohort

The objective of this study is to evaluate the effect of milk consumption, dietary calcium intake and nutrient patterns (bone-friendly and unfriendly patterns) from late adolescence to early adulthood, on bone at 22 years of age. Cross-sectional analysis was performed with 3,109 participants from 1993 Pelotas (Brazil) birth cohort in the follow-ups of 18 and 22 years of age. Bone mineral density (BMD) of the lumbar spine, right femur and whole body were assessed at 22 years using a dual-energy X-ray absorptiometry (DXA). The exposure variables (dietary calcium, milk and nutrient patterns) were created by combining the consumption frequencies between the two follow-ups (always low, moderate, high, increase or decrease). Multiple linear regressions were performed, stratified by sex. In the right femur site, men classified into the “always high” (mean = 1.148g/cm²; 95%CI: 1.116; 1.181) and “increased” categories of milk consumption (mean = 1.154g/cm²; 95%CI: 1.135; 1.174) presented a slightly low BMD comparing with low (mean = 1.190g/cm²; 95%CI: 1.165; 1.215) and moderate (mean = 1.191g/cm²; 95%CI: 1.171; 1.210) categories. In addition, men always classified in the highest tertile of the “bone-unfriendly” pattern presented the lowest mean of whole body BMD (mean = 1.25g/cm²; 95%CI: 1.243; 1.266). No associations were observed between the categories of dietary calcium intake and “bone-friendly” pattern and each of the three BMD outcomes. These results point to the fact that diets composed of inhibiting foods/nutrients can contribute negatively to bone health.

Nutritional rickets around the world: an update

Worldwide, nutritional rickets continues to be an evolving problem with several causes. This paper provides an updated literature review characterising the prevalence, aetiology, pathophysiology and treatment of nutritional rickets worldwide. A systematic review of articles on nutritional rickets from various geographical regions was undertaken. For each region, key information was extracted, including prevalence, cause of rickets specific to the region, methods of confirming the diagnosis and current treatment and preventive measures. Calcium deficiency continues to be a major cause of rickets in Africa and Asia. Vitamin D deficiency rickets is perhaps increasing in the Americas, Europe and parts of the Middle East. There continues to be a distinct presentation of calcium-predominant versus vitamin D predominant rickets, although there are overlapping features. More careful diagnosis of rickets and reporting of 25-OHD concentrations has improved accurate knowledge of rickets prevalence and better delineated the cause. Nutritional rickets continues to be an evolving and multi-factorial problem worldwide. It is on a spectrum, ranging from isolated vitamin D deficiency to isolated calcium deficiency. Specific areas which require emphasis include a consistent community approach to screening and diagnosis, vitamin D supplementation of infants and at-risk children, prevention of maternal vitamin D deficiency and the provision of calcium in areas with low calcium diets.