The decline of essential nutrients deficiencies over the past century along with the improvement in the treatment of infectious diseases has contributed to the increase in population life expectancy [1
]. However, in recent years, rates of nutrition-related chronic diseases, such as obesity, cardiovascular diseases and type 2 diabetes mellitus (T2DM) have increased, dwindling the quality of life of the population [1
Studying the nutritional situation of the population as well as lifestyle habits is fundamental to design national guidelines and public policies. Calcium, phosphorus, magnesium and vitamin D participate mainly in bone development and maintenance, but they also have other relevant biological roles [4
]. Inadequate intake and low nutritional status of calcium, magnesium and vitamin D, are well documented in many populations worldwide [5
]. Some studies have demonstrated that the consumption of low-fat milk and dairy products is inversely associated with the risk of hypertension [8
]. Likewise, several studies have shown that a higher consumption of milk and dairy products rich in calcium is associated with lower incidence of T2DM [10
]. Nevertheless, it is important to highlight that the diet is not the only factor that increases or decreases the risk of developing chronic diseases; there are other factors as the genetic background and lifestyle habits that also contribute to the risk and prevalence of these diseases.
Calcium is the main mineral involved in the structural integrity of the organism; in addition to its role in the formation and maintenance of bones and teeth, it is essential for many metabolic processes, specifically, as cell second messenger. Besides, it is necessary for the maintenance of the blood coagulation. Calcium has the highest requirements among all minerals [14
]. Phosphorus is also found in the mineral structure of bones and teeth and in soft tissues where it participates mainly in phosphorylation processes and acid-base equilibrium. Its deficiency is not common as it is present in most foods and its absorption is relatively high [15
]. Magnesium is the second most abundant intracellular cation, 70% of this mineral is in the skeleton and the rest in the cells. This mineral participates in more that 300 enzyme reactions and has similar functions as calcium, such as muscular contraction, gland secretions and nerve transmission, among others [16
]. Magnesium absorption is approx. 50%, and in general population its deficiency is not uncommon, as its intake has diminished over the years [17
Vitamin D, a fat-soluble vitamin, is the main regulator of serum calcium and phosphorus homoeostasis. It also participates in cell differentiation and proliferation and has effects on the immune and nervous system responses [18
]. Its deficiency is prevalent worldwide, but proportions vary among world regions [19
]. The main source of vitamin D is endogenous; that is to say, the daily exposure to the sun. Without vitamin D food fortification, the dietary intake of this vitamin is low [20
National diet and nutritional survey is the most used tool to assess the diet, nutrient reported intake and nutritional reported status of the population. The data collected in the surveys are mostly based on subjects self-reporting. As this method is indirect and has a pseudo-quantitative nature, the surveys frequently report data that do not represent the habitual intake of the studied population and estimate energy intakes (EI) that are not plausible physiologically [21
]. In this respect, EFSA has published a protocol that has a harmonised approach to identify misreporting [22
]. As we do in the present article, EFSA suggests that the data should be reported for the whole population as well as divided into plausible and non-plausible reporters. Additionally, it is important to mention that in recent years there has been an open discussion about the validity of the use of Memory-Based Dietary Assessment Methods (M-BMs) to collect dietary intake data [23
]. Some authors believe that the use of 24-h recall is inappropriate to calculate EI and that these data are inadmissible in scientific research and for the formulation of national dietary guidelines, while others refute these statements [23
]. It is well known that currently there is not a gold standard method to collect nutritional intake data and there is a need for an accurate scientific methodology. In this respect, some modest improvements have been made in the development of more objective tools to measure EI as digital photography or chewing and swallowing monitors; however, more research is needed to develop other objective tools [25
]. In the recent years, EFSA has published the “Guidance on the EU Menu methodology”, which is a guidance document developed to facilitate the collection of more harmonised food consumption data from all EU Member States [26
] and the present study is based on these guidelines. An additional aspect to consider is that the estimation of usual micronutrients intake using complex sample derived data from few days dietary food records, introduce excessive intra-individual variation, and to overcome this problem different statistical procedures have been reported [27
] and provide another approach to managing and analysing intake population data.
The ANIBES Spanish study aimed to evaluate energy reported intake, energy expenditure, body composition, dietary patterns and dietary quality indexes in a national representative sample of the Spanish population by using innovative methodological tools [30
]. The present article analyses the disparity between the reported consumption and the level needed for adequacy of the main nutrients involved in bone metabolism (calcium, phosphorus, magnesium and vitamin D), considering the coefficients of within-person variations for different age groups, as well as the food and beverages that contribute to their sources of intake in the Spanish population. We assessed the reported intake for both, general population and plausible reporters.
Recent studies have demonstrated that the requirements for some minerals, namely calcium and magnesium, are not being met in all age groups, mainly because of the poor quality of the diet [5
]. There are other micronutrients, such as vitamin D, that do not depend exclusively on food intake but also on other factors, such as endogenous synthesis [18
]. Nevertheless, the diet is an important source of vitamin D, especially in places with low sun exposure. The present article shows that the reported daily dietary intakes of calcium, magnesium and vitamin D are not being met by the majority of the Spanish population included in the ANIBES study. It is important to highlight that ANIBES is the first national diet and nutrition survey in Spain, reporting nutrient intake for plausible and non-plausible reporters, based on well-harmonised procedures [22
]. The ANIBES study is also based on EFSA “Guidance on the EU Menu Methodology”, guidelines designed to refine the methods and protocols described previously, and to indicate criteria for the collection of high-quality dietary information. Despite this, some authors have refuted the use of M-BMs because of the non-quantifiable nature of the error of self-reported data, and the fact that they are derived from non-empirical phenomena which are prone to omissions, false memories, intentional misreporting and misestimating [23
]. However, in the ANIBES study, we used new tools like tablets and digital cameras as more accurate and objective measures of estimating food and nutrient intakes. Likewise, two pilot studies were performed before the beginning of the main study to optimise the procedures and minimise the limitations of M-BMs.
Previously, reported ANIBES results, addressed the reported intake of energy and the main macronutrients i.e. carbohydrates, lipids and proteins [30
In the ANIBES study, the mean reported intake of calcium in all age groups was much lower than the national [35
] and European (EFSA) [36
] recommendations, even when the plausible reporters, whose reported intake was higher than the whole population, were taken separately. The calcium intake for the Spanish population in The Spanish National Survey of Dietary Intake, (Encuesta Nacional de Ingesta Dietética España, ENIDE) [44
] for adults was around 900 mg/day, with very slight differences between sexes. In the present study, the reported intake of calcium for the whole population was 698 mg/day, but 862 mg/day for the plausible reporters; this last value is very similar to the one reported in the ENIDE study [44
], although it used a different methodology. Previous studies have been performed in other European countries, indicating the consumption of calcium in the adult population. Germany [45
], the Netherlands [46
] and Finland [47
] have reported mean intakes over 1000 mg/day; France [48
], Italy [49
] and Portugal [48
] around 900 mg/day; and Greece [48
] and the UK [50
] around 850 mg/day. In general, all these countries have a low percentage of the population not meeting the recommended daily intakes [51
A recent review regarding low nutrient intake in nine European countries (Belgium, Denmark, France, Germany, the Netherlands, Poland, Serbia, Spain, and the UK) [52
] indicates that the intake of calcium in children ranges from 563 mg/day to 1106 mg/day; in adolescents from 651 mg/day to 1487 mg/day; in adults from 512 mg/day to 1329 mg/day and in older adults from 529 mg/day to 1031 mg/day. Comparing these results with those obtained in the ANIBES study, show that calcium children’s reported intake was around the mean intake of the European countries included in the review, whereas adolescents, adults, and older adults were closer to the lower intakes. When only the plausible reporters were considered, adolescents, adults, and older adults’ calcium reported intakes were higher, closer to the European countries mean intakes according to their age and sex groups, and, in some cases even superior to those values.
As expected, milk and dairy products were the main source of calcium for the ANIBES population, as was observed in the ENIDE study [44
]. However, the other foods’ groups contributed to the reported intake of calcium were in different order and proportions. It is interesting to observe that contrary to many other countries in Europe [53
], fish represents a good source of calcium for the Spanish population, specifically in the adult and elderly groups. Conversely, meat and meat products contribute only to a low percentage (3% in both Spanish studies) of the global intake of calcium.
In all studied groups, the reported intake of phosphorus met almost the totality of the Spanish [35
] recommendations as well as the European [36
]. The plausible reporter’s reported intake was adequate, and 100% of the population met the recommendations. Phosphorus is neither a shortfall nor an over-consumed mineral in this studied population. This mineral can be considered as sufficient in the majority of countries and, in some age groups even excessive [48
In contrast to the ENIDE study [44
], where fish was the main dietary source of phosphorus, in ANIBES, milk and milk products ranked first. In both cases, meat and meat products were in second place with similar percentages. However, the other food groups were positioned in a different order.
The body regulation of phosphorus is close related to calcium. The recommended intake ratios for these minerals range from 1:1 to 1.5:1. As the consumption of calcium uses to be lower than the recommended daily intake and the phosphorus higher, this ratio uses to be lower than the recommended one. Consequently, there is more predisposition to bone resorption, low peak bone mass and increased bone fragility [54
]. In the ANIBES study, the ratio for the whole population was 0.60 (0.61 for women and 0.58 for men), the same ratio as for the plausible reporters separately, very low compared with the recommendations.
The reported intakes of magnesium of the studied population were much lower than the Spanish [35
] and European [36
] recommendations, in both the whole population and the plausible reporters. The mean of the observed intake of magnesium in the ENIDE study [44
] was around 350 mg/day; adult intake was 379 mg/day for females and 409 mg/day for males. According to that survey, only 30% had an inadequate intake of this nutrient. The data from the ANIBES study were much lower, as the mean reported intake for the whole population was 222 mg/day and for the plausible reporter’s group alone 273 mg/day. This disparity might be because each study identified different patterns of consumption for food with high content of magnesium, namely cereals, legumes and nuts.
The results of surveys from most of the European countries indicated that the intake of magnesium was below the respective recommendations and that the inadequacy was higher in women than in men in some age groups, but not in all [48
]. Specifically, data from the national surveys indicated that Finnish [55
] and Swedish [56
] adult intake of magnesium was over 330 mg/day for females and over 400 mg/day for males. In the Netherlands [57
], Italy [58
] and Ireland [59
], the intake for women was between 275 mg/day and 311 mg/day and for males over 340 mg/day and under 400 mg/day; and, in France [60
] and the UK [61
], the intakes were around 250 mg/day for females and less than 325 mg/day for males. All these intakes are higher than the intakes reported for the whole population in the ANIBES; however, when we take only the plausible reporters, the intakes are similar to the data reported by France and the UK. In their review of the EU countries, Mesnkink et al. [52
] indicated that the magnesium intake in children ranged from 185 mg/day to 290 mg/day, in adolescents from 190 mg/day to 531 mg/day, in adults from 209 mg/day to 522 mg/day, and in older adults from 227 mg/day to 421 mg/day. When they excluded the under-reporters, the mean intake increased from 5% to 28% in the different age and sex groups. The ANIBES reported intake of magnesium for children was around the mean of the mentioned range, but for the other age groups, it was close to the lower reported values. However, when we took only the plausible reporters, the reported intakes increased in 10%, 12%, 24% and 38% in children, adolescents, adults, and older adults, respectively.
The main food source for magnesium reported intake in ANIBES was the group of cereals and grains, whereas in ENIDE it was the group of pulses and nuts. The remainder of the main groups that completed the list in ANIBES included milk and dairy products, meat and meat products and vegetables. However, in ENIDE [44
] the main food group that followed pulses and nuts was fish.
Spanish DRV [35
] for vitamin D are set for those individuals that have zero or very low endogenous synthesis of this micronutrient. Considering these recommendations, as well as those from EFSA [36
], the reported intake of vitamin D was by far lower than the daily recommendations in both the whole population and the plausible reporters alone. In the ENIDE study [44
], the observed intake of this vitamin was also very low, 3.65 µg/day for women and 4.28 µg/day for men. In fact, in ANIBES the reported intake was higher than in ENIDE for the whole population as well as for plausible reporters. Although the percentages of the population at risk of disparity between reported intake and the level needed for adequacy of Vitamin D in both Spanish studies were high and very similar. The same situation has been reported in most European countries. Norway is one of the countries that are above the recommendation; this is because it is mandatory, as it is in all Nordic countries, to fortify milk products and margarine, because of the relatively low sun exposure during winter months, and the potentially low sun exposure through a lifestyle that is dominated by indoor activities [52
]. In detail, the intakes of this vitamin in some European countries are: Norway over 10 µg/day [52
]; Finland [47
] and Sweden [62
] around 6 µg/day; Ireland [63
] and Portugal [51
] around 3.6 µg/day; and Italy [49
], the Netherlands [46
] and the UK [50
] around 3.1 µg/day. In general, the prevalence of vitamin D inadequacy for these countries was 40%. The ranges for the intake of vitamin D according to national surveys in nine European countries were for children 1.3 µg/day to 3.5 µg/day, adolescents 1.5 µg/day to 4.8 µg/day, adults 1.7 µg/day to 6 µg/day, and for older adults 0.7 µg/day to 5.2 µg/day. Comparing with data of the Menskin et al. review [52
], the ANIBES mean reported intakes of Vitamin D for all age groups were higher than European countries reported values. Although vitamin D3 is synthesised in the skin by the action of ultraviolet light, data from across the world indicate that hypovitaminosis D is widespread, even in those countries considered sunny, and it is currently a global major public health problem [64
]. Deficiency of vitamin D has been reported in some selected Spanish populations. This fact is perceived to be due to the use of sunscreen lotions and sedentary behaviour, which as previously mentioned, avoids frequent sun exposure [65
The ANIBES study has several strengths, which include the careful design, protocol, and methodology used, conducted among a random representative sample of the Spanish population aged 9–75 years. It is the first Spanish study at national level that analysed the data for the whole population and the plausible reporters. One limitation of this study is its cross-sectional design, which provides evidence for associations but not causal relationships [41