What is a Seriously Low Vitamin D Level?
                                
                                
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                                    4 min read                                
                            
                                According to the Endocrine Society, a serum 25-hydroxyvitamin D level below 12 ng/mL is defined as a vitamin D deficiency. This constitutes a seriously low vitamin D level, which, when chronic, can lead to significant health consequences affecting the bones and overall well-being.