3. Skin Absorption Issues
Many darker-skinned individuals have trouble due to greater amounts of melanin pigment in their epidermal layer of skin. This reduces the skin’s ability to produce vitamin D from the sun.
2. Gut Issues
Vitamin D is fat-soluble and depends on the gut’s ability to absorb vitamin D, but some medical conditions prevent this.
For instance, celiac disease, Crohn’s disease, ulcerative colitis, irritable bowel syndrome and liver disease are all usually connected to a deficiency in vitamin D. Also, those who have had bariatric surgery are less capable of absorption, since the surgery bypasses the small intestine, where vitamin D would normally be absorbed.
It has been found that vitamin D may be linked to insulin resistance. The body seems to respond better on the cell level to insulin when adequate amounts of vitamin D are present. It allows the beta cells in the pancreas to stay healthy and function better, says Jennifer Smith of Integrated Diabetes Service.
It is estimated that vitamin D deficiency is present in over one billion people worldwide, and over 40% of Americans are affected by this deficiency. Even when you are in range on blood tests, if it’s on the low end, you can still have many of these symptoms.Related: Vitamin D Deficiency Linked to Many Diseases