Digestion; Digestion and Vitamin D3 and B12

Question 1

Digestion and Vitamin B12

Answer 1

• Dietary vitamin B12 is bound to protein called R-protein, which is dependent upon the presence of pepsin and stomach acid.
• The R-B12 complex enters the duodenum and is split by pancreatic proteases (protein-digestive enzymes), which digest the R – protein and hence release vitamin B12. B12 can then bind to intrinsic factor (a glycoprotein complex), which is produced in the stomach by parietal cells
• The vitamin B12-intrinsic factor complex is absorbed in the terminal ileum into the blood
• Therefore, poor gastric and pancreatic function or damage to the ileum does impair B12 absorption

Question 2

Digestion and Vitamin D

Answer 2

• Vitamin D is synthesised in skin cells from ‘provitamin-D’ into cholecalciferol in response to UV light.
• Cholesterol (produced in the liver from dietary fats) is needed to synthesise vitamins D. Magnesium, a co-factor, converts vitamin D in the liver and kidneys.
• Alcohol/drugs impaired this process
  How to increase vitamin D in your body:
• 10 to 20 minutes of daily sun exposure.
• D3 rich foods such as oily fish or D2 rich plant-based food such as shiitake mushrooms
• Avoid alcohol, drugs, coffee and refined sugars

Question 3

The digestive tract and Vitamin D3

Answer 3

Vitamin D3 acts on the digestive system to increase intestinal absorption of calcium and phosphorus
* Vitamin D maintains calcium balance in the body, in conjunction with vitamin K2, which controls utilisation of calcium (depositing it in bones).
* 70 to 80% of ingested calcium is absorbed in the more distal regions of the small intestines (the ileum).
* Dietary vitamin D is absorbed with the help of fat. So ensure a good intake of healthy fats in the diet.
* Vitamin D helps regulate bacterial species and in the intestines. I deficiency vitamin D is linked to an imbalance of the intestinal flora, was also increasingly the likelihood of inflammatory bowel diseases.