The more vitamins, the better？
Due to the reduced exposure to sunlight and decreased outdoor activities during winter, the risk of vitamin D deficiency in the human body is heightened. Many individuals opt to take daily vitamin supplements. How should one go about supplementing vitamins, and is more always better?
Vitamins are essential nutrients that cannot be synthesized by the human body and must be obtained through dietary sources. They are broadly categorized into lipophilic vitamins (such as A, D, E, K) and water-soluble vitamins (like C and B vitamins).
Is there a benefit to taking more vitamins? Wang Chen, deputy director of the Clinical Nutrition Department at Peking University Third Hospital, warns against the misconception of “Duo Yichen.”
Wang Chen explains that an excess of certain lipophilic vitamins can lead to acute or chronic poisoning. Prolonged intake of vitamins A and D, for instance, may result in liver discomfort, fatigue, bone pain, and mental disorders. Excessive vitamin D supplementation can lead to elevated blood calcium levels and even organ calcification.
On the other hand, water-soluble vitamins can dissolve in water, and excessive intake typically prompts the body to self-adjust without causing poisoning. However, Wang Chen cautions that some water-soluble vitamin supplements may still cause physical discomfort. For instance, an overdose of vitamin C can lead to diarrhea, and exceeding 500 mg/day increases the risk of kidney stone formation.
Experts advise prioritizing vitamin intake through a balanced daily diet. If dietary requirements cannot be met, supplementation is recommended under the guidance of a nutritionist.
Preserving vitamins in food is crucial. For instance, vitamin B1, found in coarse grains, yeast, and eggs, is prone to significant loss during food processing. It is suggested not to over-cleanse rice during washing, as this helps retain more B vitamins, especially B1 and B2.
The cooking method for vegetables also impacts vitamin content. Washing vegetables before cutting reduces vitamin loss. Extended cooking times contribute to diminished vitamin levels; thus, quick cooking methods are preferable over prolonged stewing. After cooking, consuming the food promptly is advised, as prolonged storage may lead to increased vitamin loss.