Vitamin D is found in many dietary sources such as fish, eggs, fortified milk and liver oil. The sun also contributes significantly to the daily production of vitamin D and only 10 minutes of exposure is considered sufficient to prevent deficiencies. The term "vitamin D" refers to various forms of this vitamin.
Two forms of vitamin D are important in humans: ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3). Vitamin D2 is composed of plants. Vitamin D3 is synthesized by humans on the skin when exposed to ultraviolet-B (UVB) light from sunlight. Foods can be enriched with vitamin D2 or D3.
Vitamin D Needs and deficiencies
The main biological function of vitamin D is to maintain normal levels of calcium and phosphorus in the blood. Vitamin D helps in the absorption of calcium, contributing to the creation and maintenance of strong bones.
Recently, research also suggests that vitamin D can provide protection from osteoporosis, hypertension (high blood pressure), cancer and various autoimmune diseases.
Vitamin D helps your body absorb calcium, which your bones need to grow. Deficiency of vitamin D can lead to bone diseases such as osteoporosis or rickets. Vitamin D also has a role in your nervous, muscular and immune system.
Vitamin D is measured as serum levels of 25-hydroxy vitamin D. A serum hydroxyvitamin D level of 10 ng / mL is low, a level of 15 ng / mL is sufficient and a level of 200 ng / mL is potentially toxic
Rashitis and osteomalacia are classical vitamin D deficiency diseases. In children, vitamin D deficiency causes rickets, resulting in skeletal deformities. In adults, vitamin D deficiency can lead to osteomalacia, which results in muscle weakness in addition to weak bones.
Populations likely to be at high risk of vitamin D deficiency include elderly, obese, exclusively breastfed infants and those with limited sun exposure. Also, people with fat-resorption syndromes (eg cystic fibrosis) or inflammatory bowel disease (eg Crohn's disease) are at risk.
How to Get Vitamin D
You can take vitamin D in three ways: through your skin, from your diet and from supplements. Your body forms vitamin D naturally after exposure to sunlight. However, excessive exposure to the sun may lead to aging of the skin and skin cancer. So many people try to get vitamin D from other sources. You should take anywhere between 200 IU to 600 IU of vitamin D per day with the amount increasing with our age.
Vitamin D-rich foods include egg yolks, salty fish and liver. Some other foods, such as milk and cereals, have often added vitamin D.
You can also take vitamin D supplements. Contact your doctor to see how much you should take. People who may need extra vitamin D include
- The elderly
- People with dark skin
- People with certain conditions, such as liver disease, cystic fibrosis and Crohn's disease
- People who have obesity or have gastric bypass surgery
Foods with a high vitamin D content
|Liver oil, 1 tablespoon||1,360|
|Sockeye, cooked, 3 ounces||794|
|Mackerel, cooked, 3 ounces||388|
|Tuna fish, preserved in water, 3 ounces||154|
|Milk, non-fat, reduced fat and whole||115|
|Orange juice enriched with vitamin D, 1 cup||100|
|Yoghurt, fortified, 6 ounces||80|
|Margarine, fortified, 1 tablespoon||60|
|Sardines, canned in oil, drained, 2 sardines||46|
|Liver, beef, cooked, 3.5 ounces||46|
|Ready-to-eat cereals, enriched||40|
|Egg, 1 whole (vitamin D found in yolk)||25|
|Cheese, Switzerland, 1 ounce||6|
In a not very scientific research personally I have found that many women are very inadequate in vitamin D. My husband and some of my friends had to supplement a lot of vitamin D just to try to catch up