re: Are You Deficient in Vitamin D?

datadragon — 9/25/2019 9:23:24 AM

Active vitamin D levels were maintained even when patients practiced at least six years of rigorous photoprotection and not supplementing with vitamin D. More importantly, the researchers also concluded that the clinical manifestations of vitamin D “deficiency” were absent. The patients all wore protective clothing and sunscreens when outdoors. Estimated mean vitamin D intake was normal. The mean values of serum 25-OHD were low normal, but 1,25-(OH)2D, calcium, ionized calcium and parathyroid hormone levels were normal. www.ncbi.nlm.nih.gov/.../9418761

Persons with dark skin compensate for low 25(OH)D by rapidly converting it to the active 1,25(OH)2D metabolite, thus allowing them to maintain adequate vitamin D status. Skin pigmentation does not appear to negatively affect vitamin D status. They found the amount of serum 25(OH)D produced was determined by the amount of cholesterol in the skin, not on skin pigmentation. Matsuoka et al. investigated the effect of racial pigmentation on vitamin D3 formation and concluded that while racial pigmentation has a photo-protective effect, it does not prevent the generation of normal levels of active vitamin D metabolites. http://goo.gl/w2B8gU The level of 25(OH)D does not necessarily reflect the level of the active 1,25-dihydroxyvitamin-D (1,25(OH)2D) which can also be high while 25D is low as is found in inflammatory diseases. http://goo.gl/w2B8gU An interesting clinical finding is that among individuals with chronic illness such as Lyme disease/autoimmune disease, there’s a tendency for calcitriol 1,25 levels to be significantly higher than 25OH D levels. Most doctors do not test both.