Consider the following statements regarding human nutrition: 1. Spinach is a good source of vitamin A 2. Excess vitamin D in diet promotes high calcium absorption 3. One of the causes of pain in the joints is vitamin C deficiency 4. Diarrhoea is one of the symptoms of Pellagra Which of these statements are correct?

All four statements are scientifically accurate. Statement 1 is correct as spinach is a rich source of beta-carotene, a provitamin A carotenoid that the body converts into retinol [t1][t2]. Statement 2 is correct because the active form of vitamin D increases intestinal absorption of calcium; consequently, excess vitamin D (toxicity) leads to hypercalcemia, or abnormally high calcium levels [t1][t4]. Statement 3 is correct as vitamin C deficiency causes scurvy, which is clinically characterized by joint pain (arthralgia) and swelling due to impaired collagen synthesis and bleeding into joint spaces. Statement 4 is correct because Pellagra, caused by a deficiency of niacin (vitamin B3), is traditionally identified by the 'four Ds': dermatitis, dementia, death, and diarrhoea [t7]. Therefore, all statements regarding human nutrition and deficiency symptoms are valid.

Sources

1. [1] https://www.ncbi.nlm.nih.gov/books/NBK597352/
2. [2] https://en.wikipedia.org/wiki/Vitamin_deficiency