Vitamin D ~ Calciferol

PROMOTES

Bone Health

Healthy Teeth

Nervous System Function

Healthy Cell Growth: Breast, Prostate, Colon

Reabsorption of Calcium

Reabsorption of Phosphorous

PROTECTS AGAINST

Bone Loss

Loss of Calcium

Fracture Frequency

Abnormal Blood Clotting

Vitamin D production generated by the skin in the sun for twenty minutes can equal 4000iu.

Most people living in the northern areas of the U. S. are at risk for low vitamin D levels, especially during the winter months. Vitamin D supplements can help this situation. Take 400 to 800iu a day. Men and women with osteoporosis need this much on a daily basis no matter where they live.

Overview

Vitamin D was isolated in 1930. It was originally named calciferol. Over time more metabolites of this substance have been isolated. The two main forms are vitamin D2 called ergocalciferol and vitamin D3 called cholecalciferol.

Vitamin D can be manufactured in the body and therefore is not an essential nutrient as it is the action of the ultraviolet rays of the sun on the skin that converts the biological precursor 7-dehydroergosterol to vitamin D3 in animals and humans. Vitamin D2 is formed in plants from ultraviolet conversion of ergosterol.

Vitamin D is fat soluble and stored in the body fats, primarily in the liver. In the liver, the circulating form, 25 (OH) D3 is synthesized. It passes through the hepatic circulation and is reabsorbed. In the kidneys it is further hydroxilated to a more active form, 1, 25 (OH)2 D3, calcitriol or vitamin D hormone. This critical conversion phase is mostly stimulated by parathyroid hormone.

Although vitamin D is a prehormone called a secosteroid, it has continued to be classified as a vitamin because vitamin D deficiency is most commonly related to rickets even today.

Deficiency Symptoms

The classic vitamin D deficiency syndrome in children is rickets. In this disease the bone matrix is weak because insufficient deposition of calcium phosphate occurs in the environment of decreased calcium (Ca++) and phosphate (P+ ) absorption from the intestines. The bones are not strong enough to take the ordinary stress and strain of weight bearing resulting in marked bowing of the legs, knocked knees, spinal curvatures, rib cage deformities like pigeon breast and disfiguration of the skull. Poor tooth development leads to a myriad of dental problems. In adults, vitamin D deficiency can result in osteomalacia and osteoporosis.

Some of the warning symptoms of vitamin D deficiency are:

-muscle weakness

-rheumatic type pain

-gradual hearing loss

Late manifestations are pelvic and hip fractures.

Individuals who have poor fat absorption may become vitamin D deficient as the vitamin will be found in the fatty stool of these individuals. Gluten sensitive enteropathy in those with gluten intolerance and allergy are prone to this.

Drugs That Deplete:

Vitamin D should not be administered with drugs to treat hyperparathyroidism.

Also the drug that is designed to block fat absorption could affect vitamin D levels and supplementation might be needed.

See DRUG DEPLETION TABLE for specific drug information.

Food Prep To Retain:

N/A

Food Sources:

Vitamin D cannot be found occurring naturally in significant amounts in foods. Varying amounts are found in liver, eggs, butter, and cream. Salmon, sardines (canned), shrimp, & tuna are food sources.

Fortified Foods Available:

Milk is fortified with vitamin D and is the most common source in the U.S. and in many other countries, particularly in the upper northern hemisphere.

Function in the Body:

The main function of vitamin D hormone is to increase calcium (Ca++) absorption from the gastrointestinal tract along with phosphorous (P+) for the growth and regeneration of bones and teeth. It regulates serum Ca++ and P+. There are receptors for this hormone-like vitamin in many tissues.

-Bones: It is in the mineralization or formation of bones and the demineralization or mobilization of bone minerals.

-Osteoporosis: Low Ca++ levels stimulate the parathyroid gland which triggers the release of Ca++ from bone. Vitamin D hormone is needed for Ca++ to be absorbed from the intestines and keep serum levels normal.

-Cancer; It has shown some inhibitory effect on melanoma, leukemia, breast, lymphoma, and colon cancer cells.

-Immunity: It stimulated the activity of macrophages, important protective white blood cells, part of the immune system.

-General systemic inflammation: stay tuned, there is cutting edge research emerging now.

Other Facts:

During 20 minutes of sunlight exposure, the body generates approximately 4000 iu of vitamin D. In 10 minutes of summer sunlight exposure to the face and hands results in the endogenous production of about 400 iu of cholecalciferol. This process can be hampered by skin pigments, keratin or substances in the skin from drugs or applied to the skin to block ultra violet rays of the sun.

Vitamin D is important for hearing as the bones in the middle ear are susceptible to demineralization if there is deficiency. The weakened bones cannot properly transmit the vibration to the nerves that transport and interpret those vibrations into sounds.

Sunlight and ultraviolet light are helpful for people with psoriasis. Studies have suggested that vitamin D3 is supportive in the relief of symptoms of the rash and joint discomfort of this disease.

Recommended Dietary Allowance:

The RDA -recommended dietary allowance- for vitamin D is 400 international units (iu) per day. Usual daily doses range from 200 to 800 iu a day for supplementation. Doses of 1000 to 1600 iu a day are used for people with evidence of bone loss, particularly if they live in the northern regions subject to a lack of sunlight for long periods of the year. Research is showing that in some instances higher doses are more effective. Vitamin D supplementation by itself is not effective in treating osteoporosis.

RDA/AI* (Adequate Intake)

AGE (YRS) AMOUNT in micrograms (mcg) / day

Infants

0.0-0.5: 5*

0.5-1.0: 5*

Children

1-3: 5*

4-8: 5*

Males

9-13: 5*

14-18: 5*

19-30: 5*

31-50: 5*

51-70; 10 - 15*

71+: 10 - 15*

Females

9-13: 5*

14-18: 5*

19-30: 5*

31-50: 5*

51-70: 10 - 15*

71+: 10 - 15*

Pregnant: 5*

Lactating: 5*

Toxic Doses:

Excessive vitamin D intake, ranging from 3,000iu to 40,00iu in infants and 100.000iu in adults per day, over several months to years can produce toxicity. This toxicity produces hypercalcemic states. Serum calcium (Ca++) levels of 12 to 16 mg/dl are a consistent finding when toxic symptoms occur. The first symptoms are loss of appetite, nausea and vomiting, constipation, followed by polyuria (frequent, large volume urination), polydypsia (marked increased thirst), weakness, and pruritis (itching). Renal function becomes impaired due to Ca++ deposits in kidney tissue. Ca++ deposits occur in other soft tissues such as heart, lungs, arteries, and skeletal muscles. Metastatic calcification in the kidney can occur and this type of damage may be irreversible. Treatment is the discontinuation of the vitamin D supplement and a low Ca++ diet, keeping urine acidic and taking steroid drugs. Pushing fluids and administering diuretic drugs or herbs offer little help.