Research, Benefits and Cautions.
Overview:
            Vitamin D, otherwise known as the sunshine vitamin, is significant 
            in normal body growth and development. In particularly, vitamin D 
            is used to absorb calcium and phosphorus to create bone. Great sources 
            of this supplement include fortified milk, oily fish, liver, and eggs. 
            
How This Vitamin Works in Your Body:
              Absorbs calcium and phosphorus to aid in the development of bones 
              and teeth
              Promotes normal cell growth and maturation
              Prevents rickets
              Maintains a healthy nervous and immune system
              Treats low blood calcium with patients with kidney disease
              Potential reduction in breast and colon cancer
              Aging symptoms may be treated
The Following May Benefit from Taking Vitamin D:
              Kids living in places with little sunshine
              Those who need additional nutritional intake
              People over 55 who receive little sunshine, such as those in nursing 
              homes
              Pregnant or breastfeeding women
              Substance abusers
              Those under prolonged stress
              Those with partially removed intestinal tracts
              Dark-skinned individuals
              Babies who are breastfed
              Vegan vegetarians
              Cystic fibrosis patients
Where This Vitamin is Found:
              Cod-liver oil
              Egg substitutes
              Halibut-liver oil
              Herring
              Mackerel
              Salmon
              Sardines
              Sunlight
              Tuna
              Vitamin-D-fortified milk
How to Use:
              Available as:
              Liquid: the best form due to its high bioavailability and fast absorption. 
              Always choose liquid as your first choice when supplementing your 
              diet.
              Tablets: available
              Recommended Daily Intakes
              Men: 200 IU
              (over 50) 400 IU
              (over 70) 600 IU
              Women: 200 IU
              (over 50) 400 IU
              (over 70) 600 IU
              Pregnancy: 200 IU
              Lactation: 200 IU
Cautions:
              Consult your doctor if you have:
              Have planned pregnancy while taking vitamin D
              Epilepsy
              Heart or blood-vessel disease
              Kidney, liver or pancreatic disease
              Chronic diarrhea
              Intestinal problems
              Sarcoidosis
Over 55:
              Higher potential for adverse reactions and side effects. 
Pregnancy:
              Always consult doctor during pregnancy. Abnormalities within the 
              fetus may occur in too high of a dose. Remember to keep within the 
              DRI.
Breastfeeding:
              It is vital to normal growth and development of the child to get 
              the correct intake of vitamin D. Always consult doctor during lactation. 
              Remember to keep within the DRI.
Storage:
              Heat and/or moisture may alter the vitamin. Refrigeration is recommended.
Symptoms of Deficiency:
              Symptoms include bone pain and tenderness and muscle weakness. In 
              children, rickets may occur, in which bones lose calcium and become 
              soft and curved. Without proper intake, there is an increased risk 
              of osteoporosis, arthritis, and cancer. 
Overdose:
              Signs of Overdose:
              High blood pressure
              Irregular heartbeat
              Nausea
              Weight loss
              Seizures
              Abdominal pain
              Appetite loss
              Mental-and physical-growth retardation
              Premature hardening of arteries
              Kidney damage 
Side Effects:
              Reaction or effect : What to do
              Loss of appetite : Discontinue. Refer to your doctor soon. 
              Constipation : Discontinue. Refer to your doctor soon.
              Diarrhea : Discontinue. Consult doctor immediately.
              Dry mouth : Discontinue. Refer to your doctor soon.
              Headache : Discontinue. Consult your doctor immediately.
              Increased thirst : Discontinue. Refer to your doctor soon.
              Mental contusion : Discontinue. Consult your doctor immediately.
              Nausea or vomiting : Discontinue. Consult your doctor immediately.
              Unusual tiredness : Discontinue. Refer to your doctor soon.
              Interactions:
              Interacts with : Combined effect
              Antacids with aluminum : Absorption of vitamin D reduced.
              Antacids with magnesium : People with kidney failure should be aware 
              of possibly too much magnesium 
              in the blood.
              Anticonvulsants : Vitamin efficacy may be reduced.
              Barbiturates : Vitamin efficacy may be reduced.
              Calcitonin : Calcitonin effect reduced when treating hypercalcemia.
              Calcium (high doses) : Risk of hypercalcemia increased. 
              Cholestyramine : Vitamin absorption reduced.
              Colestipol : Vitamin absorption reduced.
              Cortisone : Vitamin absorption reduced.
              Digitalis preparations : Heartbeat irregularities increased.
              Diuretics, thiazide : Hypercalcemia risk increased.
              Hydration : Vitamin efficacy may be reduced.
              Mineral oil : Absorption of vitamin D increased.
              Phosphorus- containing medicines : Risk increased of too much phosphorus 
              in blood.
              Primidone : Vitamin efficacy may be reduced.
              Vitamin-D derivatives : Increased potential for toxicity due to 
              additive effects.
              Alcohol : Depletes storage of vitamin D in liver.