Calcium Flashcards
What is the RDA for 9-13 years?
1,300 mg calcium
What is the RDA for 14-18 years?
1,300 mg calcium
What is the RDA for 19-50 years?
1,000 mg calcium
What is the RDA for 0-6 months?
200 mg calcium
What is the RDA for 6-12 months?
260 mg calcium
What is the RDA for 51-70 years for women? For men?
Women: 1,200 mg calcium (due to the onset of menopause)
Men: 1,000 mg calcium
What is the RDA for 71+ years?
1,200 mg calcium for both men and women
Who established the RDAs for calcium?
FNB established the amounts of calcium required for bone health and to maintain adequate rates of calcium retention in healthy people
Build and maintain strong bones
Prevent loss of bone mass
Food sources of calcium
Dairy products: yogurt, mozzarella
Canned fish (packed with bones)
Tofu made with calcium sulfate
(TRUE/FALSE)
Calcium content varies slightly by fat content, the more fat, the less calcium it contains.
TRUE
(TRUE/FALSE)
Calcium content for tofu is processed with a calcium salt. Tofu processed with other salts does not provide significant amounts of calcium.
TRUE
(TRUE/FALSE)
Calcium is absorbed very well.
FALSE
Unfortunately, calcium is NOT very well absorbed at all, and there are several dietary factors that can inhibit calcium absorption.
What are some dietary factors that inhibit calcium absorption?
How do they inhibit absorption?
-Phytic acid
-Oxalic acid
-Any kind of unabsorbed FAs (which would probably be secondary to some type of GI chronic condition, like Crohn’s disease)
-Insoluble fiber
They bind calcium to be excreted via feces
What are the 3 forms of calcium in the blood?
- Free Ca2+
- Protein-bound calcium (prealbumin or ALBUMIN) — the majority will be bound to albumin
- Nonprotein-complexed calcium (but complex with citrate, sulfate, or phosphate)
Phytic acid
The stored form of phosphorus, found in beans, legumes, seeds, nuts, and unprocessed whole grains (outer bran layers)
TRPV6
Transporter; Calcium-channel TRPV6 located on the brush border membrane of the enterocytes.
How the majority of calcium enters the enterocytes
What ways can calcium enter the enterocytes?
- TRPV6 transporter (majority)
- Paracellular diffusion (only during times of high calcium concentrations in the intestines)
Calbindin
An important protein that will bind up calcium, once it enters the enterocyte, chaperoning it across the enterocyte, so that it can be pumped out of the enterocyte, and into the blood
(TRUE/FALSE)
Vitamin D increases the absorption of calcium.
TRUE **
How does vitamin D increase the absorption of calcium?
It can increase the expression of the TRPV6 and CALBINDIN
*These 2 proteins are very important, and the expression of these proteins is highly regulated by vitamin D.
What 2 ways can calcium leave the enterocyte during absorption?
- Calcium ATPase transporter (PMCA1b)
- Sodium calcium exchanger (NCX1) pump
Exit the enterocyte and enter the blood