Low Vitamin D Status: Definition, Prevalence, Consequences, and Correction

Abstract

Vitamin D is obtained from cutaneous production when 7-dehydrocholesterol is converted to vitamin D3 (cholecalciferol) by ultraviolet B radiation or by oral intake of vitamin D2 (ergocalciferol) and D3. An individual's vitamin D status is best evaluated by measuring the circulating 25-hydroxyvitamin D [25(OH)D] concentration. Though controversy surrounds the definition of low vitamin D status, there is increasing agreement that the optimal circulating 25(OH)D level should be ~30-32 ng/ml or above. Using this definition, it has been is estimated that approximately three quarters of all adults in the United States are low. Classically, low vitamin D status has skeletal consequences such as osteomalacia/rickets. More recently, associations between low vitamin D status and increased risk for various non-skeletal morbidities have been recognized; whether all of these associations are causally related to low vitamin D status remains to be determined. To achieve optimal vitamin D status, daily intakes of at least 1000 IU or more of vitamin D are required. The risk of toxicity with “high” amounts of vitamin D intake is low. Substantial between-individual variability exists in response to the same administered vitamin D dose. When to monitor 25(OH)D levels has received little attention. Supplementation with vitamin D3 may be preferable to vitamin D2.

Association of vitamin D insufficiency with adiposity and metabolic disorders in Brazilian adolescents

“…Vitamin D insufficiency/deficiency has been considered a public health problem worldwide because of its implications in the bone tissue, as well as in maintaining the normal homeostasis of Ca and P which is already well known (1)(2)(3) . In tropical countries this insufficiency/ deficiency has not been cited as a major concern, since cutaneous synthesis from sun exposure is the major source of vitamin D in most individuals.…”

“…An adequate vitamin D level is essential in all stages of life, and there is consensus that the best status indicator of this vitamin is the serum concentration of calcidiol (25(OH)D) (3) . Low levels of calcidiol directly affect Ca absorption and bone mineralization.…”

Effect of nutritional vitamin D preparations on parathyroid hormone in patients with chronic kidney disease

“…Initial studies [36][37][38] found that, as renal insufficiency progresses, vitamin D 2 supplementation led to less reduction in serum PTH. Patients with CKD stage 3 benefited more from VitD supplements, than those with CKD stage 4 and those on maintenance hemodialysis (HD).…”

“…Cholecalciferol therapy leads to upregulation of VitD response genes in monocytes of patients on maintenance HD, indicating that oral VitD preparations have a biologic effect on circulating monocytes and associated inflammatory markers in HD patients [33,36,49].…”

Vitamin D status and its relationship with age in type 2 diabetic patients

“…The correlation between low serum levels of vitamin D and decrease in insulin sensitivity has been reported in recent crosssectional investigations (11)(12)(13). Several epidemiological and cross-sectional investigations have detected that low levels of 25 (OH) D in circulation are related to increase of fasting blood sugar, insulin and higher prevalence of diabetes (14,15).…”