硒:好處、用途、副作用、劑量等

What is selenium?

Selenium is a mineral found in soil. It occurs naturally in water and some foods. Although people only need very small amounts of selenium, selenium plays a key role in the body's metabolism.

Selenium Benefits

Selenium has attracted attention for its antioxidant properties. Antioxidants protect cells from damage caused by environmental conditions such as aging, lifestyle choices and pollution. Over time, this cellular damage is linked to cancer, heart disease, and decreased mental skills.

Selenium supports many functions in your body, including:

  • Thyroid health. The thyroid is a small gland that produces hormones that regulate the body's metabolic processes. If you have an underactive thyroid, you may experience fatigue, weight gain, depression, and muscle pain. Over time, thyroid risks can worsen chronic conditions.

    Selenium helps maintain healthy thyroid function. But research shows that too much can damage your thyroid.

  • Cognitive support. Research shows that selenium’s antioxidant properties can combat cell damage that may worsen brain and nervous system diseases such as Parkinson’s, Alzheimer’s and multiple sclerosis. Research is ongoing to determine whether selenium can help prevent or treat the loss of mental skills. But scientists believe eating enough can help maintain healthy brain function.

Selenium has also been studied to treat dozens of other conditions. They range from asthma to arthritis to prostate cancer to infertility. The results of these studies are inconclusive.

How much selenium should you take?

The Recommended Dietary Allowance (RDA) includes the total amount of selenium you should get from food and any supplements you take. Most people can get the recommended daily amount of selenium from food.

The safe upper limit of selenium for adults is 400 micrograms per day. Anything above this is considered an overdose.

group
Recommended dietary intake
Children 1-3 years old 20 micrograms/day
Children 4-8 years old 30 mcg/day
Children 9-13 years old 40 mcg/day
Adults and children over 14 years old 55 mcg/day
pregnancy period 60 mcg/day
during breastfeeding 70 mcg/day

Selenium-containing foods

The amount of selenium in a food depends largely on the soil conditions in which the food is grown.

Good food sources of selenium include:

1. Brazil Nuts

Brazil nuts are the most potent source of selenium. But portion control is important. Just one nut contains 95 micrograms, nearly twice your daily requirement. Doctors recommend no more than 400 micrograms of selenium per day to avoid potential health risks.

2.Seafood

Most seafood contains large amounts of selenium. White fish such as yellowfin tuna and halibut contain about 92 micrograms of the mineral per 3-ounce serving, while the same serving of canned sardines has 45 micrograms.

3.Lean meat

Meat is an excellent source of many essential nutrients, including selenium. The selenium content of fried chicken breast is as high as 35 micrograms, and if you eat the skin, you can get an additional 5 micrograms of selenium. Lean beef varieties are also a good choice. A 4-ounce serving of skirt steak contains 26 micrograms of selenium.

4. Pasta

Pasta is an easy way to add selenium to most diets. A cup of cooked pasta contains 36 micrograms, while whole-wheat varieties contain up to 50 micrograms.

5. Rice

Since most rice is gluten-free, it may be a good choice for people with wheat allergies or celiac disease. One cup of cooked white rice contains 9 micrograms of selenium. But you can get about 15 micrograms from a cup of brown rice.

6. Eggs

Large eggs provide about 28% of your daily selenium needs. Most are found in egg yolks. If you're watching your cholesterol intake, egg whites also contain about 9 micrograms of selenium.

7. Oatmeal

Whether you make it a breakfast bowl, use it to thicken smoothies, or use it to replace flour in baked goods, oatmeal is an excellent source of selenium. A cup of ready-to-eat oatmeal contains 10 micrograms of selenium, while raw oats have up to 23 micrograms.

8. Baked beans

Baked beans (including vegetarian products) contain approximately 12 micrograms of selenium per cup. Beans are also a great source of fiber, but canned beans contain a lot of sodium. Eat in moderation to avoid the health risks of a high-sodium diet.

What are the risks of taking selenium?

Our bodies need selenium to function properly, but there are risks to adding more selenium to your diet, including:

  1. side effect. When taken in normal doses, selenium usually does not cause side effects. Overdose of selenium may cause bad breath, hair loss, fever, fatigue and nausea < ai=5 >.
  2. interaction. Selenium may also interact with other medications and supplements you take, such as some antacids, chemotherapy birth control pills, cholesterol-lowering statins and niacin medications, corticosteroids,
  3. skin cancer . Selenium supplements may be associated with the risk of skin cancer (squamous cell carcinoma), so people at high risk for skin cancer should not take these supplements.

Selenium toxicity

A little bit of selenium is usually enough to meet your daily needs. In the long term, regularly reaching unsafe levels can lead to selenium toxicity, a condition linked to respiratory problems, kidney failure and heart problems. At high enough levels, selenium toxicity can even be fatal.

Selenium deficiency

Selenium deficiency is rare among healthy people in the United States. But certain health conditions - such as HIV or Crohn's disease - put you at higher risk for low selenium levels. People who are fed intravenously are also at risk for selenium deficiency.

Symptoms of selenium deficiency include:

  • Headache
  • nausea
  • Confused
  • fatigue
  • attack
  • along with

Selenium deficiency may cause:

  • Male infertility and male birth-specified infertility
  • Keshan disease (a type of heart disease)
  • Kashin-Beck disease (a type of arthritis).

Selenium supplement

If you are deficient in selenium, your doctor may recommend taking a selenium supplement.

These supplements usually come in capsule or tablet form. But whole foods are the best sources of selenium, as this mineral can be destroyed during processing. Unless your doctor tells you to take a supplement, get your selenium from food to avoid getting too much.

Review

All comments are moderated before being published

HealthyPIG Magazine

View all
小朋友叫唔應?可能唔係無禮貌,而係科學:專注時真係聽唔到你

小朋友叫唔應?可能唔係無禮貌,而係科學:專注時真係聽唔到你

小朋友一睇YouTube、打機、畫畫,突然叫佢,佢完全聽唔到。係咪扮聾?係咪發展遲緩?抑或專注力問題? 研究顯示,大部分情況完全正常,與腦部的「選擇性注意力(Selective Attention)」同「過度專注(Hyperfocus)」有關,不代表有疾病。 什麼是「選擇性注意力」?(Sele...
高血壓|隱形殺手的成因、統計數據與科學研究

高血壓|隱形殺手的成因、統計數據與科學研究

  高血壓|隱形殺手的成因、統計數據與科學研究 快速導讀 高血壓係全球最普遍、但最容易被忽視嘅慢性病之一。 超過一半患者完全無症狀,但長期會破壞血管、增加中風同心臟病風險。 主要成因包括:高鹽、肥胖、缺乏運動、低鉀、飲酒、睡眠窒息症、壓力、吸煙、腎病等。 全球研究顯示:高鹽攝取加上肥胖...
為何肺癌早期大多沒有症狀?科學原理、風險因素與早期發現方法全解析

為何肺癌早期大多沒有症狀?科學原理、風險因素與早期發現方法全解析

肺癌一直是全球最常見、死亡率最高的癌症之一。令人憂心的是,大部分肺癌患者在早期(第一、二期)都沒有明顯症狀,往往直到腫瘤擴散、壓迫周邊結構或影響呼吸功能後才被發現。本文以科學角度深入講解:為何肺癌早期「靜悄悄」、身體不察覺?身體內部究竟發生了甚麼? 亦會加入實際的自我檢查策略與醫學建議。 一...
黑眼圈成因全解析:從生理、生活習慣到醫學對策

黑眼圈成因全解析:從生理、生活習慣到醫學對策

前言:為何黑眼圈總是揮之不去? 「黑眼圈」係現代人嘅常見問題之一。無論係通宵工作、壓力過大、過敏,甚至遺傳因素,都可能令眼底皮膚變黑或出現陰影。雖然多數情況屬於美容問題,但有時亦可能反映身體狀況,例如貧血、睡眠質素差、血液循環不良等 [1]。  一、黑眼圈的主要類型與成因 色素型黑眼圈(Pi...
智慧手錶 vs 專用 O₂Ring 血氧儀:血氧監測能力的科學比較

智慧手錶 vs 專用 O₂Ring 血氧儀:血氧監測能力的科學比較

1. 前言 血氧飽和度(SpO₂)是評估呼吸、循環系統狀態的重要指標。近年來,市面上兩大類可穿戴設備用於血氧監測: 智慧手錶(如 Samsung Watch、Apple Watch) 專用血氧監測設備(如 O₂Ring、指夾式脈搏血氧儀) 兩種設備的設計目的、測量方式、準確性、監測...
血氧飽和度、氧氣下降與「警戒線」的科學探討

血氧飽和度、氧氣下降與「警戒線」的科學探討

1. 前言 血氧飽和度(SpO₂)即血液中氧合血紅蛋白佔總血紅蛋白的百分比,是臨床及居家監測呼吸、循環功能的重要指標。當血氧飽和度下降,可能反映體內氧的供應或運送出現問題(低氧血症、hypoxemia)或更廣泛的組織缺氧(hypoxia)[1][2]。本文旨在探討: 血氧飽和度正常範圍與變...
冰敷(Cold Therapy)真正作用全面解析:止痛、減腫,還是幫助修復?|科學視角 + 實證文獻

冰敷(Cold Therapy)真正作用全面解析:止痛、減腫,還是幫助修復?|科學視角 + 實證文獻

冰敷(Ice Pack / Cold Therapy / Cryotherapy)係好多運動、急性受傷(如扭傷、撞擊、肌肉拉傷)時的第一時間處理方法。但不少人會疑惑: 「冰敷純粹止痛,定係真係會幫助組織修復?」「冰敷幾耐?冰敷幾多日?會唔會影響身體自然修復?」 本文從科學、醫學、運動治療角度,...
長時間保持同一姿勢後關節痛、僵硬、郁唔到:成因、科學解釋與改善方法

長時間保持同一姿勢後關節痛、僵硬、郁唔到:成因、科學解釋與改善方法

前言:為何「坐耐、蹲耐、跪耐」之後會痛? 無論係坐喺電腦前、跪低執嘢、長時間翹腳、側睡又唔郁——好多人體驗過一樣情況: 「一動就痛、一企起身腳軟、膝蓋直唔到、關節卡卡聲,又或者要行幾步先鬆返。」 其實呢種情況係非常普遍,而且通常並非關節已經壞死,而係 和關節生理、滑液循環、血液供應、肌肉張力 ...
魚醒味的科學:成因、風險與處理方法全面解析

魚醒味的科學:成因、風險與處理方法全面解析

「魚醒味」是華人烹飪文化中常見的說法,用以描述魚類在 解凍、切片或加熱後所突然出現的腥味、血水味或脂肪味。此現象並不代表食材變壞,但背後牽涉到蛋白質變化、脂肪氧化與揮發性化合物釋放等多種科學機制。本文將以科學角度剖析魚醒味的成因,並提供實證方法降低這種味道,同時探討其安全性。 🧪 什麼是「魚...