While it is not entirely clear why some people produce less collagen, there are several factors that can cause a decrease in collagen production. These include:
Too much sun exposure : Sunlight is a natural source of vitamin D, which helps in increasing the production of collagen. If you are exposed to too much sunlight, then it may cause degradation in the bone tissue and also reduce the production of collagen.
Age : As we age, our bodies tend to lose their elasticity and strength. As a result, they start losing their ability to recover from injuries as well as other harmful conditions. Thus, due to this reason, collagen production starts decreasing with time.
Diet: Certain foods can stimulate inflammation and make it worse. Foods that contain omega-6 fats (like vegetable oils), trans fats (found in many processed foods), saturated fats (found in meat), and inflammatory omega-6 fatty acids (found in some nuts) can all promote inflammation and make it worse. On the other hand, fruits and vegetables are rich in antioxidants that have anti-inflammatory properties. These include vitamins A, C, E, beta-carotene, lutein/zeaxanthin, lycopene, and quercetin.
Smoking: Smokers have higher rates of several types of cancer compared to non-smokers. Smoking also increases your risk of developing heart disease and stroke. Smoking increases oxidative stress in your body — which can lead to long term damage to your collagen production system as well as other tissues throughout your body such as skin health or nails
Stress: Stress is a major cause of decreased collagen production. The body produces collagen in response to stress, which helps repair tissue and build immunity.
Stress can be physical or emotional, and can come from work, money problems, family issues, or even a bad day at the office. When you're stressed out about something, your body releases hormones that can make it harder for your body to produce collagen.
You may also be more likely to experience this effect if you have an illness or other health condition that makes it hard for your body to heal itself.