John Cannell, MD

For a number of reasons, many people aren’t getting enough vitamin D to stay healthy. This is called vitamin D deficiency.

The two main ways to get vitamin D are by exposing your bare skin to sunlight and by taking vitamin D supplements. You can’t get the right amount of vitamin D your body needs from food.

When vitamin D comes into your body, it goes through all sorts of processes and is turned into different forms to be effective. In this article, we’ll teach you a little about this process, and how vitamin D works in the body.

Nearly every cell in the body contains a vitamin D receptor. Research shows vitamin D plays an important role in skeletal, immune, developmental and cardiovascular health. Thus, maintaining optimal vitamin D levels is vital for overall health.

Acne is a disorder of the glands which lubricate the skin, called sebaceous glands. When these glands become blocked, bacteria overgrow and causes skin lesions.

Although most people take vitamin D supplements without any problems, it’s possible to take too much. This is called vitamin D toxicity.

Pharmacology is the branch of medicine that is focused on the use and study of drugs and their actions.

Melanoma is a type of cancer originating in the melanocytes. Melanocytes are cells that produce melanin, which gives skin its pigment (color).

When most people think of calcium, they think it’s most important for bone health. But actually, calcium is most important for your nervous and muscular system.

Getting the right nutrients and eating well when you’re pregnant or breastfeeding is important for your baby’s growth and development.

Asthma is a lifelong lung disease that makes it difficult to breathe. There are tubes or airways, which carry air to and from the lungs to the mouth and nose.

Colorectal cancer is a malignant tumor, which is caused by a group of cancerous cells growing in either the colon or rectum.

Vitamin K describes a family of compounds with a common chemical structure. Review of vitamin D's interaction with vitamin K and combined supplementation.

Stomach (gastric) cancer is a moderately important cause of disease and death. Review of vitamin D's potential role in prevention and disease progression.

Heart failure is also called congestive heart failure (CHF). CHF occurs when the heart can no longer pump enough blood to the rest of the body.

Coronary heart disease (CHD) is one of several cardiovascular diseases. The others include stroke, congestive heart failure, and peripheral artery disease.

Leukemia is a cancer of the blood or bone marrow. The disease causes an abnormal increase of white blood cells. There are many types of leukemia.

Ovarian cancer is cancer that starts in the ovaries. As it has few symptoms at first, it is often diagnosed at more advanced stages.

Tuberculosis is a respiratory illness that usually affects the lungs, but can also infect the kidney, spine, or brain. Tuberculosis can be either dormant or active.

Respiratory infections are any infection in the throat, sinuses, airways, or lungs. The respiratory tract is the part of the body that is involved with breathing.

For most people, supplementing with vitamin D is a safe and healthy practice. Review of rare hypersensitivity reactions, contraindications, and dose adjustments.

We all feel fed up, miserable and sad at certain times in our lives. Most of the time, these feelings last for a few days, or maybe a week,

Having blood tests to measure the amount of vitamin D in your blood is the only way to know if you’re getting enough vitamin D or not. The blood test you need is called a 25(OH)D blood test.

The way that vitamins and minerals work in your body is interconnected. How well vitamin D works depends on the amount of other vitamins and minerals that are present in your body. The other vitamins and minerals needed to help vitamin D work well are called cofactors.

Vitamin D is important for good overall health, strong bones, and immune function. Overview of synthesis, sources, deficiency risks, and supplementation guidance.

As the reader will see below, there is compelling evidence that low vitamin D status during pregnancy is a major cause of autism,

Eczema, also known as atopic dermatitis, is a chronic skin disorder that causes inflammation and red, dry, rough, and itchy skin.

Multiple myeloma (MM) is a cancer of the plasma cells. They are white blood cells that normally produce antibodies.

Hypertension, also known as high blood pressure, is a medical condition in which the blood pressure in the arteries is elevated.

Lung cancer is a cancer starting in the lungs. Lung cancer is the leading cause of cancer death in the United States.

The answer is a resounding YES, not only because there are positive clinical trials showing that vitamin D prolongs life,

Each year, kidney (renal) cancer affects approximately 61,000 Americans and kills about 13,000. Review of vitamin D research on kidney cancer outcomes.

Cervical cancer starts on the surface of the cervix. This is the lower part of the uterus (womb), which opens at the top of the vagina.

Chronic obstructive pulmonary disease (COPD) is one of the most common lung diseases. There are two main forms of COPD:

Cognitive dysfunction is defined as unusually poor mental function. This causes confusion, forgetfulness and difficulty concentrating.

Dental caries, also known as tooth decay, is a tooth infection caused by bacteria that leads to a loss of the hard tissues of your teeth.

Fibromyalgia is a chronic syndrome of body-wide pain. Tender points are the joints, muscles, tendons, and other soft tissues.

Endometrial cancer is cancer that starts in the endometrium, the lining of the uterus (womb). Each year, endometrial cancer affects approximately 46,000 U.S.

Parkinson’s disease (PD) is a chronic progressive neurological disease. It is linked to decreased production of dopamine, a nerve transmitter.

Periodontal disease (PD) is a chronic gum condition. Bacteria cause the gums to swell, redden, and bleed. Connective tissue holding the teeth into the jaw bone may become damaged.

The prostate is a small gland found in men. It is about the size of a walnut and is part of the reproductive system.

Preeclampsia is a condition which occurs only during pregnancy and a short post-pregnancy period. It causes increased blood pressure and protein in the urine.

Sepsis is a severe illness. It is caused by a bacterial infection that begins anywhere in the body and moves to the blood. The bloodstream is soon overwhelmed by bacteria.

Alzheimer’s disease (AD) is a condition that causes memory problems and other cognitive functions that cause unpredictable changes in behavior.

The marker for vitamin D status is 25-hydroxyvitamin-D [25(OH)D], a metabolite of vitamin D3. Review of measurement methods, reference ranges, and interpretation.

Anaphylaxis is a very severe hypersensitivity to an allergen. Allergens are any substances that cause allergies. This condition affects many systems of the body at the same time.

Osteoporosis is a condition where you lose too much bone or don’t make enough bone to replace the bone that you normally lose.

Inflammatory bowel disease is a chronic disease that causes inflammation in all or part of the digestive tract.

Anemia occurs when the body has a low number of red blood cells (RBCs). These cells carry oxygen throughout the body. Fewer RBCs limit the body’s oxygen level.

Yes, you should — studies show that vitamin D helps reduce the risk of colds and flu. Review of clinical evidence on immune response and seasonal infection.

Type 1 diabetes is an autoimmune disease. It is a condition where your own immune system attacks certain cells called beta-cells.

Human immunodeficiency virus (HIV) causes acquired immunodeficiency syndrome (AIDS). The immune system begins to fail. This leads to life-threatening infections.

Multiple sclerosis is a condition where the body’s immune system attacks the nerves in the brain and spinal cord.

Type II diabetes is a condition in which the body has a hard time managing sugar. Review of clinical research on vitamin D status and insulin sensitivity.

Systemic lupus erythematosus (SLE), or lupus, is a chronic disease that affects many systems in the body, such as the skin, heart and muscles.

Esophageal cancer is a moderately important cause of disease and death. In the United States each year, it affects about 17 thousand people and kills approximately 15 thousand.

Pancreatic cancer is cancer of the pancreas, the organ that produces insulin. Approximately 44,000 people in the United States are diagnosed with cancer of the pancreas each year.

Pneumonia is a lower respiratory infection that affects the lungs. Pneumonia can usually be treated at home in a few weeks.

Rickets is a condition that affects the development of bones in children. It causes soft weak bones, which can become bowed or curved.