What is Vitamin D?
Vitamin D (VD) is also called as D or solar hormone. It has an important role in the development, growth, and maintenance of a healthy body from birth to death. Mankind needs sun exposure for vitamin D requirements in life. Season, latitude, daytime, skin pigmentation, aging, customary clothing, sunscreen, glass, obesity have an effect on the production of vitamin D. Vitamin D is important for calcium absorption from the bowel. The avoidance of sun exposure increases vitamin D deficiency risk.
Vitamin D Deficiency and Recommended Daily Intakes of Vitamin D
Vitamin D is metabolized in the liver and then in the kidney to 1.25-dihydroxyvitamin D [1.25(OH)2D]. 1.25(OH)2D receptors are presented in the intestine and bone. These receptors are settled in other tissues such as the brain, heart, stomach, pancreas. Vitamin D deficiency is a major unrecognized health problem. It is caused rickets in children. Also, osteomalacia and osteoporosis are observed in adults. Moreover, chronic vitamin D deficiency may give serious adverse consequences such as hypertension, multiple sclerosis, rheumatoid arthritis, cardiovascular disease, metabolic syndrome, cancers, breast, prostate, ovary, and diabetes.
Vitamin D deficiency can be correlated with accelerated aging and longevity of the life span. The levels below 20 ng/mL of VD defines vitamin deficiency. Monitoring of serum 25OHD3 concentrations can help reveal of vitamin D deficiencies. Sensible sun exposure prevents vitamin D deficiency (10-20 minutes for the arms, 3-4 times for legs and face a week). The recommendation of daily intakes of vitamin D 1000 IU or 2000 IU is reasonable approaches to guarantee vitamin D sufficiency. Table 1 shows recommended amount of vitamin D per day.
Table. 1 Recommended amount of vitamin D per day
|Age||Recommended amount of vitamin D per day:|
|0 to 1 year||400 IU|
|1 to 70 years||600 IU|
|Over 70 years||800 IU|
Great Sources of Vitamin D
The major source of vitamin D for children and adults is natural sunlight. Thus, the major cause of vitamin D deficiency is inadequate exposure to sunlight. Wearing a sunscreen with a sun protection factor of 30 reduces vitamin D synthesis in the skin by more than 95%. Some foods are fortified as sources of vitamin D (Table 2).
Table. 2 Food Sources of Vitamin D
|Food||Serving Size||Amount of Vitamin D|
|Salmon, Atlantic, cooked||75 g||246 IU|
|Salmon, chum, canned||75 g||202 IU|
|Tuna, yellowfin, cooked||75 g||105 IU|
|Milk||250 mL||104 IU|
|Tuna, canned, light||75 g||36 IU|
|Egg yolk||1 egg||32 IU|
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