The feedback loops communicate with the body to ensure homeostasis.
Answer is A. Feedback Loops 
It will help you
Have a great day
        
                    
             
        
        
        
Inadequate dietary vitamin D or its deficiency leads to malabsorption of calcium. Nutritional disorder leads to the rare disease rickets, which causes bones to become soft and bend in children. In adults, vitamin D deficiency leads to osteomalacia, which causes weak bones, bone pain and muscle weakness. 
The body needs vitamin D to properly absorb calcium and phosphorus from the diet. However, keeping the right quantities of calcium and phosphorus in bones is challenging when vitamin D levels are low. 
The two sources of vitamin D are-
- Natural sunlight 
- Foods such as fish oil, Egg yolk and fatty fishes like salmon and mackerel
There are other disease conditions which lead to poor absorption of vitamin D-
- Inflammatory bowel disease
- Celiac diseases
- Kidney problems
To learn more about Rickets here-
brainly.com/question/26292489
#SPJ4
 
        
             
        
        
        
Living things in the environment such as plants, animals, and bacteria are biotic factors. Biotic factors also include once-living parts such as dead leaves on the forest floor. Abiotic factors are nonliving aspects of the environment such as sunlight, temperature and water. One important abiotic factor is soil.
        
             
        
        
        
Answer:
- A, B, C and D are: elements or molecules
- A and B are: reactants
- C and D are:  products
Explanation:
The expression "A + B <--> C + D" represents a chemical equation. A chemical equation represents the "mixture" of molecules or elements that will react and form other molecules and elements, so we can say that A, B, C and D represent molecules or elements.
But not only that. In a chemical equation, the elements and molecules that are before the symbol "<-->" represent the reagents in the equation. Therefore, A and B are the reagents. The elements or molecules found after the symbol "<-->" are the products of the reaction. Therefore, C and D are the products.
 
        
                    
             
        
        
        
Lack of exercise 
High blood pressure 
Diabetes 
Obesity and high cholesterol