Umum mengetahui bahawa kalsium diperlukan untuk pertumbuhan tulang dan menggantikan sel-sel tulang yang musnah bagi memastikan densiti tulang kuat dan menghalang osteoporosis (reput tulang).
Apa pula kaitan antara kalsium dan vitamin D?
Vitamin D diperlukan oleh badan bagi menyerap kalsium daripada makanan, jika tidak, kalsium yang dihasilkan oleh makanan akan dikeluarkan daripada badan sebagai bahan kumuh/buangan.
Oleh itu kedua-dua kalsium dan vitamin D bekerjasama bagi mengekalkan densiti tulang yang secukupnya, di samping fungs-fungsi lain seperti membantu perjalanan ritma denyutan jantung yang normal, memastikan otot berfungsi dengan baik, terlibat dalam aliran darah serta perembesan hormon dalam badan.
Seperti mineral lain, badan kita tidak boleh membuat kalsiumnya sendiri, oleh itu ia perlu diperolehi melalui makanan yang dimakan seperti bahan tenusu (susu, keju, yogurt), sayuran lain (bayam, bendi, kacang soya), ikan (sardin, salmon, trout), dan makanan ringan yang diperkaya dengan kalsium (jus oren, oatmeal, sereal).
Sebaliknya, vitamin D agak sukar diperolehi melalui makanan dalam kuantiti yang banyak. Beberapa sumber vitamin D yang telah dikenalpasti dalam makanan termasuklah ikan berasid lemak (tuna, tenggiri, salmon), dan bahan yang diperkaya dengan vitamin D seperti produk tenusu, jusu oren, susu soya, sereal, hati lembu, keju, kuning telur, dsb.
Berbeza dengan kalsium, vitamin D boleh dibuat oleh badan kita iaitu dengan bantuan cahaya matahari. Oleh itu, orang yang tinggal di negara tropika, tidak akan mengalami kekurangan vitamin D.
Jumlah keperluan kalsium dan vitamin D sehari oleh kanak-kanak dan dewasa dikongsi dalam artikel di bawah ini…. semoga bermanfaat.
Top Food Sources for Calcium and Vitamin D
Reviewed by Louise Chang, MD
To keep your bones strong, your body is constantly breaking down old bone cells and growing new ones, just as it sheds and replaces skin cells. To fuel bone growth, keep bone density strong, and prevent osteoporosis, you need a good supply of calcium from dairy products and other foods in your diet.
But you also need enough vitamin D. Without it, you could drink milk all day long and the calcium in it wouldn’t do you much good. Vitamin D is key in absorbing calcium from the food you eat — calcium that would otherwise get sent out of the body as waste.
Along with weight-bearing exercise, calcium and vitamin D go together for good bone density — and good health in general. Here’s some advice on how to get more calcium and vitamin D in your diet.
Food Sources of Calcium and Vitamin D
Your body doesn’t make calcium on its own. The best way to get more calcium is to improve your diet. You already know that dairy products — such as milk, cheese, and yogurt — are good sources of calcium. Other foods that are high in calcium include:
Some fish, like sardines, salmon, perch, and rainbow trout
Foods that are calcium fortified, such as some orange juice, oatmeal, and breakfast cereal
It’s a lot harder to get enough vitamin D from foods. Vitamin D is only in a few foods and often in very small amounts. Foods that provide vitamin D include:
Fatty fish (like tuna, mackerel, and salmon)
Foods fortified with vitamin D, like some dairy products, orange juice, soy milk, and cereals
Getting enough vitamin D from your diet isn’t easy. Studies show that only about 20% of our vitamin D typically comes from the foods we eat.
Your body can also make vitamin D on its own. When you walk out into the sunlight with exposed skin, your body naturally produces vitamin D on its own.
How to Get Enough Calcium and Vitamin D
How much calcium and vitamin D do you need? The Institute of Medicine has released the following guidelines:
Young children 1-3 years old should get 700 milligrams (mg) per day.
Children 4-8 years old should get 1,000 mg per day.
Children 9-18 years old should get 1,300 mg of calcium a day.
Adults up to age 70 should get 1,000 mg per day. Women 51 and over should get 1,200 mg/day.
Women and men 71 and over should get 1,200 mg per day.
How does this translate into your daily diet? A 45-year-old could easily get her recommended 1,000 mg of calcium daily by eating:
1 packet of fortified oatmeal (100 mg)
1 cup of skim milk (305 mg)
8 ounces of non-fat yogurt (452 mg)
½ cup of spinach (146 mg)
600 international units (IU) per day for children from age 1 to adults through age 70
800 IU per day for people 71 and older.
To get vitamin D from food, fish is the best option. Six ounces of cooked salmon has more than 600 IU — more than the recommended amount for any age. Other foods containing vitamin D include eggs, liver, fortified dairy products, and fortified juice.
Your doctor may recommend higher levels of calcium and vitamin D, especially if you are at risk for osteoporosis. The National Osteoporosis Foundation recommends that adults under age 50 get 400 – 800 International Units (IU) of vitamin D every day, and that adults age 50 and older get 800 – 1,000 IU of vitamin D every day.
Calcium and Vitamin D Supplements
Ideally, experts say we should get the nutrients we need from whole foods and a well-balanced diet, rather than from supplements. That way, we’re getting the full benefits of the food instead of a single, isolated component.
In practice, it’s not always so simple. Calcium and vitamin D supplements can be important for some people. As we get older, it’s harder for our bodies to make new bone as quickly as it’s destroyed. For women, that’s especially true after menopause. Getting older also makes it more difficult to absorb calcium and synthesize vitamin D.
Talk to your doctor if you are interested in taking a calcium or vitamin D supplement. Together, you can figure out if it’s necessary. Consider these questions:
How much calcium is in your diet? Your doctor might want you to work out how much calcium you’re getting from foods. You can do this by keeping a food journal for a few days.
Could I be vitamin D deficient? Because most of our vitamin D doesn’t come from diet, a food diary won’t help determine your vitamin D levels. If your doctor suspects a deficiency, he may order a blood test.
Should you get more time in the sun? Could sunscreen and wide-brimmed hats explain why some people are deficient in vitamin D? Many experts think so. As we’ve become more concerned about the risk of skin cancer, we’re getting less sun exposure — and producing less vitamin D as a result. Talk with your doctor about sun exposure and skin cancer risk.
Are you at risk of getting too much calcium or vitamin D? Very high intake of calcium — 2,500 mg or more for people 19-50 and 2,000 mg or more for people 51 and older — may increase the risk of kidney problems and block the absorption of minerals. There’s less agreement about how high people can go with vitamin D: 4,000 IU is considered the highest tolerable intake for adults before there is increased risk for harm.
What sort of supplements are available?
There are different types of calcium supplements and vitamin D supplements available — such as calcium citrate and calcium carbonate, and vitamin D2 (ergocalciferol) and D3 (cholecalciferol). Current evidence suggests that there’s not a big difference between them, although some research has found that vitamin D3 might be more effective than D2. Calcium carbonate can be more difficult to absorb on an empty stomach or if you have low levels of stomach acid compared to calcium citrate, so it should be taken with food. Again, your doctor can advise you on the right supplements for you.
Could you have a hidden calcium or vitamin D deficiency? Even people who seem like they should be getting enough calcium and vitamin D sometimes aren’t. Why? Some medicines and health conditions can block the normal absorption of calcium or vitamin D. Talk to your doctor about any potential problems that might put you at risk for low levels of calcium or vitamin D.
Beyond Bone Density: Other Calcium and Vitamin D Benefits
Calcium and vitamin D aren’t only important for bone health. Calcium helps keep heart rhythms normal and maintains muscle function. It also is involved with blood flow and the release of hormones in the body.
Many experts believe that vitamin D deficiency is becoming more common and that it has potentially serious health risks. Besides bone problems, low levels of vitamin D are connected with muscle weakness and immune function. Some studies have shown that a low level of vitamin D is associated with a higher risk of diseases like colon cancer and rheumatoid arthritis.