Write the functions, sources and the effects of deficiency of the following nutrients: a) Vitamin D b) Vitamin C c) Calcium

a) Vitamin D

• Function: Vitamin D helps regulate calcium and phosphate levels in the body, which are crucial for maintaining bone health and strength. It also plays a role in supporting immune function and cell growth.
• Sources: The primary source of vitamin D is sunlight exposure, which triggers its synthesis in the skin. Additionally, it can be obtained from certain foods such as fatty fish (e.g., salmon, mackerel), egg yolks, fortified dairy products, and fortified cereals.
• Effects of Deficiency: Deficiency of vitamin D can lead to weakened bones and increased risk of bone disorders like rickets in children and osteomalacia or osteoporosis in adults. Muscle weakness, increased susceptibility to infections, and mood disturbances are also associated with vitamin D deficiency.

b) Vitamin C

• Function: Vitamin C is essential for the synthesis of collagen, a protein vital for skin, blood vessels, bones, and cartilage. It acts as an antioxidant, helping protect cells from damage caused by free radicals. Vitamin C also supports immune function and aids in the absorption of iron.
• Sources: Excellent sources of vitamin C include citrus fruits (e.g., oranges, lemons), strawberries, kiwi, bell peppers, broccoli, and tomatoes.
• Effects of Deficiency: Deficiency of vitamin C can lead to scurvy, characterized by fatigue, swollen gums, joint pain, and poor wound healing. Severe vitamin C deficiency can result in bleeding gums, skin rashes, and impaired immunity.

c) Calcium

• Function: Calcium is crucial for building and maintaining strong bones and teeth. It also supports proper muscle function, nerve transmission, and hormone secretion.
• Sources: Good dietary sources of calcium include dairy products (milk, cheese, yogurt), leafy green vegetables (such as kale, spinach), tofu, almonds, and fortified foods like orange juice and cereals.
• Effects of Deficiency: Calcium deficiency can lead to osteoporosis, a condition characterized by fragile bones prone to fractures. Insufficient calcium intake can also cause muscle cramps, numbness or tingling in extremities, and poor dental health. Additionally, long-term calcium deficiency may increase the risk of hypertension (high blood pressure) and other cardiovascular conditions.