2. Introduction
This presentation will focus mainly on the role of
calcium intake and the manifestations of calcium
deficiencies.
3. Nutrients
Nutrients are essential and all play a key role to
survival of the human organism.
Water
Energy yielding nutrients
Carbohydrates, Protein, Lipids (Fat)
Vitamins (organic)
Fat soluble, Water soluble
Minerals (inorganic)
Macro, Trace
5. What is Calcium
Calcium is the most abundant mineral in the body
This mineral is naturally found in foods, added to some,
available as a dietary supplement, and present in some
medicines
Most of the body’s calcium is found in bones and teeth.
Estimated to be 99% of calcium in the body
Approx 1.5-2% of the body weight
An adequate intake helps grow a healthy skeleton in
early life and minimize bone loss later in life
6. Calcium in Bones
Calcium salts form crystals called hydroxyapatite on
a matrix of the protein collagen.
Mineralization of calcium, phosphorus, and other
minerals crystallize and harden the bones.
The bones gain strength and rigidity as they harden.
7. Calcium in Bones
Bones are not like solid rock
Bones gain and lose minerals continuously in an
ongoing process of remodeling.
The balance between bone resorption and deposition
changes with aging.
The lack of homeostasis can lead to manifestations of
clinical problems and cause a disease state.
8. Calcium in Body Fluids
%1 of the body’s calcium circulates in the fluid as
ionized calcium that is vital to life.
The serum calcium is highly regulated and doesn’t
fluctuate with variations in dietary intakes
Calcium also activates a protein called calmodulin
Calmodulin (a inactive protein) is activated by calcium
It then becomes a messenger that tells other proteins
what to do and serves as an interpreter for hormone and
nerve mediated messages arriving at cells
9. Calcium in Body Fluids
vascular contraction and vasodilatation
muscle function
nerve transmission
intracellular signaling
hormonal secretion
Role in maintaining normal blood pressure
10. Recommended Dietary Allowance (RDA):
RDAs for the amounts of calcium required for bone health and to maintain adequate rates of calcium retention in healthy people.
Table 1: Recommended Dietary Allowances (RDAs) for Calcium [1]
Age Male Female Pregnant Lactating
0–6 200 mg 200 mg
months*
7–12 260 mg 260 mg
months*
1–3 years 700 mg 700 mg
4–8 years 1,000 mg 1,000 mg
9–13 years 1,300 mg 1,300 mg
14–18 years 1,300 mg 1,300 mg 1,300 mg 1,300 mg
19–50 years 1,000 mg 1,000 mg 1,000 mg 1,000 mg
51–70 years 1,000 mg 1,200 mg
71+ years 1,200 mg 1,200 mg
* Adequate Intake (AI)
11. Foods that Contain Calcium
Calcium is found in a variety of foods.
Dairy Foods
Milk, yogurt, and cheese are the most popular choice in the US.
Leafy Greens
Kale, broccoli, and Chinese cabbage are vegetable source
Fish
Canned sardines and salmon
Most grains (such as breads, pastas, and unfortified cereals),
while not rich in calcium, add significant amounts of calcium to
the diet because people eat them often in large amounts.
Fortified foods
Breakfast cereals, fruit juices, soy(Silk) and rice beverages, and
tofu.
12. Medicines that Contain Calcium
The two main forms of calcium in supplements are
carbonate and citrate
Calcium carbonate is found in some over-the-counter
antacid products, such as Tums® and Rolaids®.
13. Calcium Balance
Homeostasis of calcium is one of the body’s most
important priorities.
Bone tissue is used as a reservoir and a source of calcium,
to maintain constant concentrations of calcium in muscles,
blood, and intercellular fluids.
Vitamin D and other hormones play a essential role as
well in balancing levels
Three organs play a key role in calcium levels
1. The intestines
2. Bones
3. Kidneys
14. Calcium Balance
Parathormone (Parathyroid hormone)
A hormone from the parathyroid glands that regulates
blood calcium by raising it when levels fall too low
Calcitonin
A hormone from the thyroid gland that regulates blood
calcium by lowering it when levels rise too high
16. Absorption of Calcium
Calcium is absorbed by all parts of the small
intestine
Two mechanisms of absorption
Active transport and passive diffusion
It is best absorbed in an acidic medium
Lactose and vitamin D enhances calcium
absorption
The efficiency of absorption decreases as
calcium intake increases
17. Likelihood of Deficiency
Dietary surveys indicate that many people do not meet the
Adequate Intake for calcium, especially women
Consuming foods to maintain adequate vitamin D status
improve absorption
Dietary inadequacy is not likely if protein and calcium intake
are adequate
Stimulants in coffee and tea can discreetly increase calcium
excretion and reduce absorption in the GI tract
Phytic acid found in whole-grain breads can decrease
availability
18. Lab Values for Nutritional
Assessment
The normal levels for ionized (free) Ca2+
4.64-5.28 mg/dL
The normal levels for total serum Ca2+ (bound and
unbound)
8.6-10 mg/dL
Status is related to many factors, including vit D, vit
K, phosphate, parathyroid function, and medications
19. Lab Values for Nutritional
Assessment
Hypercalcemia (High Calcium Levels)
Associated with endocrine disorders, malignancy, and
hypervitaminosis D
Hypocalcemia (Low Calcium Levels)
Associated with Vit D deficiency and inadequate hepatic or
renal activation of Vit D, hypoparathyroidism, magnesium
deficiency, renal failure, and nephrotic syndrome
20. Hypoparathyroidism
Hypoparathyroidism is the
result of a decrease in
production of parathyroid
hormones by the parathyroid
glands located behind the
thyroid glands in the neck.
Usually occurs after a surgery
where the parathyroid glands
are removed.
The result is a low level of
calcium in the blood or
hypocalcemia.
21. Assessment Tools
Dual-Energy X-ray absorptiometry (DXA) is thought to be
one of the best tools for assessing bone mineral density
Very important in early detection, treatment, and
monitoring of osteoporosis
Preferred approach for measuring BMD
Measures bone mineral content at axial and appendicular sites
Monitors changes over time
Low radiation exposure
Superior quality control procedures
Computerized tomography (CT) scans measure variances
in tissue density. This method is less precise and accurate
than DXA
22. Osteoporosis (Adult
Bone Loss)
Disease in which the bones become porous and
fragile due to a loss of minerals
Bone strength is a function of two factors
Bone mineral density and bone quality
BMD is determined by peak bone mass and BQ
relates to bone architecture, bone turnover,
mineralization, and the accumulation of damage to
the bone
Peak in bone mass= late 20’s early 30’s
23. Classification
Primary-not related to other disease
Mostly seen in middle aged females and older
men/females
Males have greater bone mass
Secondary-identifiable cause other than age or
menopause is present
Cushing’s syndrome, myeloma, hyperthyroidism,
amenorrhea, medicines( thiazide diuretics and heparin)
24. Osteoporosis
• Leads to a greater risk of fractures
• Fractures in the hip, vertebrae, pelvis,
humerus, distal forearm
• Females more likely to have fractures
25. Five Steps to Optimize Bone Health
1. Maintain a balance diet rich in calcium and vitamin
D.
2. Participate in regular, weight-bearing exercise.
3. Practice a healthy lifestyle with no smoking or
excessive alcohol intake
4. Talk to health care professional about bone health
5. If indicated, obtain bone mineral density testing
and take medication, if appropriate
26. In conclusion
Calcium is the most abundant mineral in the body
and is mostly found in bones and teeth.
%1 of the body’s calcium circulates in the fluid as
ionized calcium that is vital to life and homeostasis
Many people become deficient in calcium especially
those suffering from illness and the elderly
It is important for dietitians to thoroughly evaluate
patients for calcium defiency and provide
nutritional intervention if needed.
27. References
Chung M, Balk EM, Brendel M, et al. Vitamin D and Calcium: A Systematic Review
of Health Outcomes. Rockville (MD): Agency for Healthcare Research and Quality
(US); 2009 Aug. (Evidence Reports/Technology Assessments, No. 183.) 1,
Introduction. Available from: http://www.ncbi.nlm.nih.gov/books/NBK32605/
National Institutes of Health. Optimal calcium intake. NIH Consensus Statement:
1994;12:1-31. [PubMed abstract]
2 Overview of Calcium." Dietary Reference Intakes for Calcium and Vitamin D.
Washington, DC: The National Academies Press, 2011.
Ross AC, Manson JE, Abrams SA, Aloia JF, Brannon PM, Clinton SK, Durazo-Arvizu
RA, Gallagher JC, Gallo RL, Jones G, Kovacs CS, Mayne ST, Rosen CJ, Shapses SA.
Clarification of DRIs for calcium and vitamin D across age groups. J Am Diet Assoc.
2011 Oct;111(10):1467. [PubMed abstract]
U.S. Department of Agriculture, Agricultural Research Service. 2011. USDA National
Nutrient Database for Standard Reference, Release 24. Nutrient Data Laboratory Home
Page,http://www.ars.usda.gov/ba/bhnrc/ndl.