The secret of vitamin D: It not only nourishes bones, but also protects the intestines. Nutritionists deeply analyze its magical effects and medical research!

The role of vitamin D

Vitamin D helps the body absorb calcium and phosphate from food and is an important vitamin that promotes muscle and bone growth. When we eat calcium-rich foods, the gastric acid in the stomach will dissociate the calcium in the food into calcium ions, which are then absorbed in the small intestine. If vitamin D is added, it can stimulate the production of calcium transport proteins and increase the absorption rate of calcium. Humans must get enough vitamin D from foods such as fish, liver, eggs, and sun exposure.



How to Get Vitamin D from Sunlight

Skin exposed to sunlight can produce vitamin D. Generally, it is best to sunbathe between 11 a.m. and 3 p.m., as the wavelength of ultraviolet light during this time can produce enough vitamin D. The angle of sunlight is lower in the early morning or afternoon, so 10-15 minutes of sunbathing during the noon period is enough. It is recommended to wear shorts and a shirt, and it is best if more than 70% of the body is exposed to the sun.

3 Types of People Who Are Prone to Vitamin D Deficiency

1. People with darker skin have skin (melanin) that acts as a natural sunscreen and increases the time they need to be in the sun to naturally produce vitamin D.

2. People whose skin is rarely exposed to sunlight, such as by staying indoors for long periods of time or wearing covering clothing.

3. People with liver disease, kidney disease, or those with food absorption problems (such as cystic fibrosis, celiac disease, inflammatory bowel disease) and certain medications (such as some epilepsy medications) may have a harder time absorbing and controlling vitamin D levels.

Vitamin D and Gut Health

A recent study pointed out that vitamin D is not only a good helper for calcium supplementation, but also can improve intestinal health and maintain intestinal microecology.

Some evidence suggests that vitamin D can modulate inflammatory bowel disease (IBD) and influence the gut microbiome.

In a clinical trial of humans with inflammatory bowel disease (IBD), the relapse rate was reduced from 29% to 13% in the group that received 1,200 IU of vitamin D per day for one year, compared with a placebo group (which received a neutral substance in the experiment).

Epidemiological studies have shown that individuals with higher serum vitamin D levels have a lower incidence of IBD, as vitamin D can alter the transcription of antimicrobial peptides and DEFB4 (defense peptide, β4), thereby affecting the intestinal microbiome.

Many cell types of the immune system express vitamin D receptors, so vitamin D has a certain potential for use in immune regulation. In addition, vitamin D deficiency can lead to dysbiosis of the intestinal microbiota and can lead to severe colitis.

To date, there is not enough clinical evidence to show that vitamin D supplements are effective in treating IBD, but there is sufficient evidence that they can help the intestinal environment and reduce the severity of IBD.

References:

Seyed-Amir Tabatabaeizadeh, 2018 Aug, J Res Med Sci., Vitamin D, the gut microbiome and inflammatory bowel disease, 23:23:75. doi: 10.4103/jrms.JRMS_606_17. eCollection 2018.