Vitamin D deficiency
Description, Causes and Risk Factors:
Vitamin D, the “sunshine vitamin,” is a hormone that is important to many aspects of good health. Unfortunately, lack of adequate vitamin D (vitamin D deficiency) is a serious problem for people living around the world.
Vitamin D3 (cholecalciferol).
- Vitamin D2 (ergocalciferol).
Vitamin D plays an important role in many normal body functions, including:
Regulation of cell growth.
- Bone formation.
- Immune function.
- Muscle strength.
- Hair growth.
- Fighting infections.
- Reducing the risk of autoimmune diseases.
Vitamin D comes from:
Exposure to sunlight.
- Certain fish and fish oils are good sources of vitamin D.
- Vitamin D supplements which can be bought over-the-counter (without a prescription) are available in 400 IU (international units), 600 IU, 700 IU, 800 IU, and 1000 IU tablets.
Vitamin D deficiency may be secondary to multiple etiologies including decreased dietary intake or absorption, reduced exposure to sun, increased hepatic catabolism, decreased endogenous synthesis, and end-organ resistance. Vitamin D deficiency has also been linked to the pathogenesis of osteoporosis and hip fractures as well as other skeletal and non-skeletal disorders.
Certain diseases of the digestive system can cause malabsorption of vitamin D from food in the intestines. These include Crohn’s disease, celiac disease, and cystic fibrosis. Obesity and gastric bypass surgery can also lower vitamin D stores in the body. Disease such as renal failure and liver failure can also cause substantial reduction in serum vitamin D binding protein. Vitamin D deficiency is also associated with increased morality in type 1 diabetic patients.
Vitamin D insufficiency affects normal cellular proliferation and differentiation and may thus affect risk of cancer. Observational evidence suggests that people who get little or no exposure to sun tend to have higher rates of breast, colon and prostate cancer; some experts believe this is the result of marginal vitamin D status.
Risk factors may include extreme latitudes, advanced age, disabilities such as pervasive developmental delay, mental retardation, people who are dark skinned, cystic fibrosis, vegan diet, being breast fed.
Patients with vitamin D deficiency may present with symptoms of hypocalcemia. This includes neuromuscular irritability, convulsions, tetany, and paresthesias.
Symptoms of vitamin D deficiency may include:
- Delayed tooth formation.
- Dental deformities.
- Muscle cramps.
- Poor growth in children.
- Spine and other bone deformities.
- Stooped posture and a loss of height.
Likeall diagnoses the physician must confirm it orrule it out by means of history, physical examination andlaboratory assessment.The findings of muscle weakness and pain on physical examination are nonspecific, and often are misdiagnosed as fibromyalgia.The most sensitive test to diagnose vitamin D deficiency is the serum 25-hydroxyvitamin D level.PTH levels are normal in early or mild vitamin D deficiency.Only later do the findings of prolonged secondary hyperparathyroidism present (i.e., osteomalacia, osteoporosis).
Key clinical recommendation:
Patients with no sun exposure, malabsorption, or those taking antiepileptic drugs may require larger maintenance doses of vitamin D (i.e., up to 50,000 IU one to three times weekly).
- Dietary Intake: Vitamin D deficiency can be prevented, and the treatment can be made effective by the consumption of natural foods that are a rich source of vitamin D. These include foods like eggs, beef liver, fish and fish oils (like cod liver oil), cow’s milk, soy milk, etc.
- Artificial Ultraviolet B Radiation: This form of treatment is administered to those who do not have access to direct sunlight. Exposure to ultraviolet B radiation, created by artificial light sources, works as a substitute for direct sunlight exposure, and allows the synthesis of vitamin D by the skin.
- Daily vitamin D supplementation of 800 to 1,000 IU is a reasonable dose for adults.
- Levels of 25-hydroxyvitamin D should be maintained above 32 ng/mL (80 nmol/L) to maximize bone health.
- In patients with severe vitamin D deficiency (serum levels of below 8 ng/mL with hypocalcemia), 50,000 IU of vitamin D should be given daily for one to three weeks, followed by weekly doses of 50,000 IU.
- After repletion of body stores, 800 IU of vitamin D daily or 50,000 IU of vitamin D once or twice monthly is adequate maintenance therapy.
- In critically ill patients, albumin-adjusted calcium levels underestimate true or ionized hypocalcemia. Therefore, measured ionized calcium levels are recommended, particularly in patients who are being treated in an intensive care unit.
- If calcium supplementation alone fails to maintain normal serum levels, the patient is vitamin D deficient or resistant and may benefit from a trial of calcitriol (Rocatrol).
- If the vitamin D deficiency is severe, the patient will require 90 mmol/L in the first 24 hours: 6 mL of K2PO4 added to each liter of fluid and given at 200 mL/hr (1 mL of K2PO4 is equal to 4 mEq of potassium and 3.0 mmol/L or 93 mg of phosphate).
NOTE: The above information is educational purpose. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition.
DISCLAIMER: This information should not substitute for seeking responsible, professional medical care.