Sources and Absorbability
By Cathy DeHaan - Twin Beaks®
While most bird keepers are aware of the repercussions of a calcium-deficient diet, many are uninformed of the dangers of too much calcium. Excess calcium from supplements, fortified foods and high-calcium diets, can cause the "milk alkali syndrome," which has serious toxicity and can be fatal. Excessive calcium intake can lead to hypercalcaemia (an elevated calcium level in the blood), complications of which include vomiting, abdominal pain and altered mental status.
- High calcium intakes can lead to constipation, an increased chance for developing calcium kidney stones, and may inhibit the absorption of iron and zinc from food.
- Too much calcium can cause the shell glands in the uterus to over-produce calcium, sometimes making the shells to adhere to the uterus, making it difficult (if not impossible ) for the hen to lay the egg.
Symptoms of Hypocalcaemia (low calcium) are:
- Poor eggshell formation
- Poor bone health
- Unhealthy heart
Symptoms of Hypercalcaemia (elevated calcium levels) are:
- Calcification of the kidneys
- Chicks unable to hatch out of shell
- Abdominal pain
Twin Beaks® Aviary's practice of allowing birds free choice (what, when and how much) is especially conducive in regards to proper calcium intake, as problems can arise from both providing too little and too much calcium in their diet.
Food sources of Calcium for your bird are:
- Dark green, leafy vegetables
- Dandelion (found in abundance in Herb Saladtm)
- Oatstraw (found in abundance in Herb Saladtm)
- Marshmallow root
Popular supplemental sources of Calcium for your bird are:
- Oyster shell
- Cuttlefish bone
- Mineral block
*Transporter proteins in eggshell calcium significantly enhance bioavailability making eggshell calcium 20% more absorbable than other forms of calcium carbonate.3 In addition, natural ultra-refined eggshell calcium avoids typical digestive discomfort. 4
Adequate vitamin D3, phosphorous and magnesium intake is necessary to enable proper calcium absorption. Commercial supplements and additives are one way of providing these nutrients, a natural and organic diet plus sufficient sunlight, is another.
Several rich sources of magnesium for your bird are:
- Sunflower seed
- Darkgreen, leafy vegetables, i.e. broccoli, spinach
- Corn and cornmeal
- Oatstraw (found in abundance in Herb Saladtm)
- Plantain (also found in abundance in Herb Saladtm)
Vitamin D is naturally available in only a few foods. It can be difficult to get all the vitamin D needed from food alone. Full spectrum lighting such as blacklights and Vita-Lites provide effective and adequate supplementation to sunlight.
Sources of Vitamin D are:
- Full-spectrum lighting**
- Fish oil
- Egg yolk
*While window glass absorbs a lot of the necessary ultraviolet radiation needed to form Vitamin D, sunlight does pass through glass. The Sun emits ultraviolet radiation in the UVA, UVB, and UVC bands, but because of absorption in the atmosphere's ozone layer, 98.7% of the ultraviolet radiation that reaches the Earth's surface is UVA. Ordinary glass is partially transparent to UVA but is opaque to shorter wavelengths. Ordinary window glass passes about 90% of the light above 350 nm, but blocks over 90% of the light below 300 nm. UVA (sunlight, blacklight) falls in the 400nm – 320-nm range. 5, 6, 7
**Incandescent lighting marketed as full spectrum can produce the same beneficial lighting as that produced by specially designed fluorescent bulbs. This is untrue: Incandescent lights provide a general lighting solution for work areas and living spaces. They are not full spectrum.
"Successful bird-keeping and breeding is quite possible through proper housing, complete, balanced, and natural-food diets, and appropriate mate selection." - Cathy DeHaan
- Ilan Gabriely et al, N Engl J Med, 1 May 2008, 358(18):1952
- 9/04 AZ1042 THE UNIVERSITY OF ARIZONA COLLEGE OF AGRICULTURE TUCSON, ARIZONA 85721
- Daengprok W, Garnjanagoonchorn W, Naivikul O, Pornsinlpatip P, Issigonis K and Mine Y: Chicken eggshell matrix proteins enhance transport in the human intestinal epithelial cells. (J Agric Food Chem 2003, 51:6056-6061)
- Schaafsma A and Beelen GM: Eggshell calcium is a comparable or better source of calcium than purified calcium carbonate. (J Sci Food Agric 1999, 79: 1596-1600)
- "Soda Lime Glass Transmission Curve
- "B270-Superwite Glass Transmission Curve" www.pgo-online.com/intl/katalog/curves/B270_kurve.html
- "Selected Float Glass Transmission Curve" www.pgo-online.com/intl/katalog/curves/whitefl_kurve.html
© Copyright 2008 Twin Beaks Aviary
Twin Beaks® neither encourages nor discourages the use of medicines, supplements or vitamins. We have just alternately chosen to practice prevention and provide naturally and organically, rather than man-made." - Cathy DeHaan