Which statement characterizes acute glomerulonephritis?

A. Iron is a critical component of hemoglobin, the molecule in red blood cells (RBCs) that carries oxygen. Without sufficient iron, the body cannot produce enough healthy RBCs, leading to anemia.

B. Fiber is important for digestive health but does not play a role in red blood cell synthesis.

C. Magnesium is involved in many biochemical processes but is not directly required for RBC synthesis.

D. Calcium is important for bone health and various cellular functions, but it is not directly involved in red blood cell production.

E. Folic acid (vitamin B9) is essential for DNA synthesis and cell division, both of which are crucial for the production of red blood cells in the bone marrow.

F. Potassium is vital for maintaining cellular function, especially in muscles and nerves, but it is not required for RBC synthesis.

A. Rheumatoid arthritis also involves morning stiffness and symmetrical joint pain, but it typically affects smaller joints first (e.g., hands, wrists), and does not usually cause Heberden's and Bouchard's nodes, which are more characteristic of osteoarthritis.

B. Osteomalacia involves bone softening due to vitamin D deficiency and does not present with joint nodes or the type of stiffness described.

C. Osteoarthritis is a degenerative joint disease characterized by morning stiffness, limited range of motion, and joint pain that worsens with activity. Heberden's and Bouchard's nodes are specific to osteoarthritis, typically appearing on the fingers.

D. Rickets is a pediatric disorder caused by vitamin D deficiency, leading to bone deformities, but it does not cause the joint issues or nodes described.