Periwinkles, a type of small sea snail, offer several nutritional benefits. They are a good source of protein, iron, and calcium, which are important for muscle health, blood health, and strong bones, respectively. They also contain omega-3 fatty acids, which are beneficial for heart and brain health. Additionally, periwinkles provide various vitamins like A, E, and B complex vitamins, including B1, B3, B6, and B12, along with choline, which is crucial for nerve function and brain health. 

Here's a more detailed look at the nutritional benefits:

Protein: Periwinkles are a good source of protein, which is essential for building and repairing tissues, and supporting various bodily functions. 

Iron: The iron in periwinkles is important for red blood cell formation and carrying oxygen throughout the body, helping to prevent fatigue and anemia. 

Calcium: Calcium is vital for maintaining healthy bones and teeth. 

Omega-3 Fatty Acids: These healthy fats play a crucial role in heart and brain health. 

Vitamins: Periwinkles provide Vitamin A (good for eye health), Vitamin E (an antioxidant and potential support for reproductive health), and various B vitamins (including B1, B3, B6, and B12) which are important for energy production, nerve function, and may help with diabetes prevention and control. 

Choline: This nutrient is essential for nervous system function and maintaining brain health. 

Phosphorus: Periwinkles are high in phosphorus, which is important for energy metabolism and the health of teeth and gums.