Vitamin D Deficiency

By Meg Mangin

Studies of healthy subjects have found levels of 25(OH)D that, by some vitamin D standards, are declared deficient (hypovitaminosis-D). [1] In a 2009 meta-analysis of studies on healthy subjects worldwide, the mean 25(OH)D was 21.62 ng/ml. [2] In a 2006 study, 80% of healthy Bangladeshi women had a 25(OH)D level under 16 ng/ml. [3] A…

Vitamin D ‘Deficiency’ – Bacterial Etiology

By Meg Mangin

Vitamin D proponents use a disease deficiency model to explain low levels of 25(OH)D. Their hypothesis states low 25(OH)D causes chronic diseases; however, a pathogenesis has not been elucidated. Low serum 25(OH)D in the presence of disease can also be explained with a dysregulated vitamin D metabolism model. This hypothesis proposes that low vitamin D…

Vitamin D and Rickets

By Meg Mangin

Rickets is a disease of the hypertrophic chondrocytes in the skeletal growth plate resulting in a softening of bones in children. Rickets is characterized by impeded growth and deformity of the long bones. (Osteomalacia is the milder, adult form of the disease. Osteomalacia symptoms include diffuse body pains, muscle weakness, and fragility of the bones.)…

Vitamin D

By Meg Mangin

The five forms of vitamin D are collectively known as calciferol; the primary forms are vitamin D2 and vitamin D3. “Vitamin D” is a generic term that can mean either D2 or D3 and may also be used to refer to the metabolites formed from calciferol. Chemically, vitamin D is a steroid that functions as…

Vitamin D Photosynthesis and Elderly Skin

By Meg Mangin

As the skin ages, there is a decline in the cutaneous levels of 7-dehydrocholesterol, resulting in a marked reduction of the skin’s capacity to produce vitamin D3. [1] However, Vanderschueren et al. concluded that renal capacity to synthesize 1,25(OH)2D, in addition to 25(OH)D production in the skin in response to sunlight, may be relatively well…