Mis à jour : 3 août 2020
Vitamin D is a fat soluble vitamin that plays a vital role in the human body. It has many functions, and a lack of vitamin D can lead to many health problems.
Vitamin D is essential in bone growth. Its main role in the body is to increase the flow of calcium into the bloodstream. It does this by promoting absorption of calcium from food. Without vitamin D, calcium would not be absorbed into the body. Therefore, vitamin D is equally important to the maintenance of bone health as is calcium.
Osteomalacia refers to a marked softening of your bones, most often caused by severe vitamin D deficiency. Osteomalacia in children is known as rickets. The softened bones of children and young adults with rickets can lead to bowing during growth, especially in weight-bearing bones of the legs. Osteomalacia in older adults can lead to fractures. Rickets and osteomalacia are different manifestations of the same underlying pathological process.
Osteomalacia differs from the more-common condition of having a low vitamin D level. Osteomalacia also differs from osteoporosis, which causes bone thinning.
Treatment for osteomalacia involves providing enough vitamin D to harden and strengthen (mineralise) bones, and treating underlying disorders that might cause the condition.
Vitamin D has other roles in the body. It is used in the maintenance of several organ systems as well as the immune system. Because of its important functions, vitamin D deficiency can lead to many other health problems. Heart disease, arthritis, diabetes, high blood pressure, and even cancer have been associated with a lack of vitamin D. Additionally, new studies suggest that vitamin D may play a role in protecting against Alzheimer's and Parkinson's disease.
An average healthy adult between the ages of 19 and 50 should receive about 200 IU's of vitamin D a day. Older adults should have higher levels to ensure proper bone maintenance. Recommendations for those between the age of 51 and 70 is 400 IU and 600 IU for people over the age of 70. However, these numbers are low level recommendations to avoid severe deficiency. In most cases, higher levels are healthy. Vitamin D toxicity is very unlikely.
Vitamin D is naturally produced in the human body when exposed to sunlight. Limited sun exposure has been a leading cause of vitamin D deficiency. Depending on season, geographic latitude and time of day, you can receive an adequate amount of vitamin D simply by going outside. On average, 15 - 20 minutes of sunlight will provide you with a daily amount of vitamin D.
The other way to get vitamin D is through your diet. Nondairy (plant milk) is usually fortified with vitamin D. However, it will not provide you with the recommended level. Therefore, other foods should be incorporated into the diet. Mushrooms and fortified cereals are also good sources of vitamin D.