Wednesday, December 7, 2011

Vitamin D - The Sunshine Vitamin

Vitamin D or calciferol is classified as a fat-soluble vitamin but has properties of a hormone and vitamin.  Oil-soluble vitamins can become toxic if taken in megadoses.  Vitamin D is called the "sunshine" vitamin because it is manufactured in the human skin when in contact with ultraviolet light from the sun's rays.  Vitamin D is related structurally to the hormones estrogen and cortisone.     

Main Functions and Uses:
Regulates calcium metabolism and normal calcification of the bones.
Helps increase the absorption of calcium from the intestines.
Necessary for thyroid function.
Necessary for normal blood clotting.
Helps maintain normal blood levels of calcium and phosphorus.
Important in the prevention and treatment of breast and colon cancer.
Normal growth and development of bones and teeth in children.
Prevents and cures rickets.
Prevents tooth decay.
Important in the prevention and treatment of osteoporosis, osteoarthritis, bone fractures, and hypocalcemia.
When taken with Vitamin A, has been used in the treatment of diabetes, cataracts, visual problems, allergies, sciatia pain, and skin problems.

Signs of deficiency:
Chronic pain, chronic kidney disease, Crohn's disease, hyperthyroidism, osteoporosis, osteopenia, osteomalacia, and rickets.

Signs of toxicity:
Vitamin D is a fat-soluble vitamin so excessive amounts may cause toxicity.  Common symptoms include excessive thirst, diarrhea, weakness, headaches, and bone pain.  Other symptoms may include abnormal calcification of soft tissues.  Symptoms usually decrease and disappear when megadoses are stopped.

Natural and food sources:
The sun is the best source of Vitamin D so get out in the sun for 20 minutes 3 or 4 times per week.  When that is not possible, Vitamin D is found in egg yolks, butter, fortified cereals and milks, salmon, sardines, tuna, herring, oatmeal, sweet potatoes, and shiitake and canterelle mushrooms.  For vegetarians, when sun exposure is not possible, it is wise to take a supplement to get enough vitamin D. 

Best supplement sources:
Fish or cod liver oil (Carlson's), Vitamin D3 (cholecalciferol), and Vitamin D2 (ergocalciferol).  Vitamin D3 is an animal source and Vitamin D2 is a plant source.  Vitamin D2 must convert to Vitamin D3 in the body and has limited functions, therefore Vitamin D3 is the preferable form because it is easily converted to the fully active Vitamin D3. 

Recommended daily amount:
400 IU - children
800 IU - adults
1,000 IU - adults 50+ or any menopausal woman

Vitamin D is best utilized by the body with Vitamin A so take it WITH a whole food mult-vitamin or IN a whole food multi-vitamin. Remember to combine what is already in the multi-vitamin with the oil if you are taking both. If you need 800 IU and your multi-vitamin has 400 IU, then you need to add another 400 IU from another source if you are not getting any sun exposure. Some multi-vitamins already have 800 IU of Vitamin D since the FDA has increased the minimum daily requirement.

Fish oil capsules

Drugs that interferes with absorption of Vitamin D - cholesterol lowering drugs, antacids, steroid hormones such as cortisone, and diuretics.
If you have liver disease, intestinal disorders, and gallbladder malfunction interfere with the absorption of Vitamin D.

Image: tungphoto /

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