Vitamins and minerals can help you stay in good shape as you age. Ideally, you should get all your nutrients from unprocessed whole fruits, vegetables and other foods. But your dietary needs change with age. Older adults have different needs when it comes to vitamins and minerals.
It can be a challenge for some older people, especially if you are not eating a balanced diet caused by Lack of appetite, Trouble chewing, Trouble finding healthy foods,… And even in some cases, age-related illnesses can be the cause.
In addition to the risks of malignancy and peptic ulcer, acid-free stomach and severe forms of atrophic gastritis may associate with failures in absorption of essential vitamins, like vitamin B12, micronutrients (like iron, calcium, magnesium and zinc), diet and medicines.
As you age, you can start to lose more of this mineral than you take in. Calcium helps your muscles, nerves, cells and blood vessels to function well. You get most of it from your bones, which get it from food. Milk, yogurt and cheese are good sources.
Calcium strengthens your bones and is found in dairy products like milk and yogurt.
Calcium from carbonate and citrate are the most common forms of calcium supplements. Calcium carbonate, the most cost-effective form, should be taken with a meal to ensure optimal absorption. Calcium citrate can be taken without food and is the supplement of choice for individuals with achlorhydria or who are taking histamine-2 blockers or protein-pump inhibitors.
The recommended daily allowances (RDA) varies with age, gender, and other factors. For men or women at risk for fracture or osteoporosis, calcium requirement is 1,200 mg calcium (diet + supplements) and 1,000 – 2,000 IU’s of vitamin D  . Women are at greater risk for the osteoporosis than men are and may need to take additional measures.
Talk to your doctor to make sure there are no other issues or contraindications with other medications that may affect how you absorb calcium.
Vitamin B12Vitamin B12 is a nutrient that helps keep the body’s nerve and blood cells healthy and helps make DNA, the genetic material in all cells. Vitamin B12 also helps prevent a type of anemia called megaloblastic anemia that makes people tired and weak. 
People over 50 should get most of their vitamin B12 from fortified foods or dietary supplements because, in most cases, their bodies can absorb vitamin B12 from these sources.
You get it naturally from animal foods like meat, fish, eggs, and dairy. Pills, shots, and “B12-fortified” foods, like breakfast cereal, are other sources.
Vitamin D helps your body take in and use calcium. It also helps you prevent bone loss and broken bones in older adults. Vitamin D also helps your muscles, nerves, and immune system work right. This nutrient, made by the body from the sun, helps in the absorption of calcium and phosphorus, so it is essential for healthy bones and teeth.
Older adults don’t, too, so supplements can help lower your risk of bone loss and fractures. But your body is less able to convert sun’s rays to vitamin D as you age. Many experts suggest that ≥1000–2000 IU [25–50μg] of vitamin D daily is necessary for older people, especially when independence is lost, or hypovitaminosis D could add to the clinical problem[s]. Much higher doses than these are needed for treatment of established deficiency or insufficiency.
It’s harder to get this vitamin from foods, but fatty fish like salmon, mackerel, and sardines are a good source.
You can get it from tuna, mackerel, beef liver, cheese, milk, figs, and egg yolks.
Magnesium helps your body make proteins and bones and keeps your blood sugar stable. You can get it from nuts, seeds and green leafy vegetables, spinach and dairy products, and it is used to fortify certain breakfast cereals.
But the elderly tend to eat less. In addition, they are more likely to have long-term health problems or to take many medications, both of which may be lacking in magnesium.
Among other things, it helps keep your blood pressure and blood sugar at a constant level.
A study in 2006 showed that the serum magnesium concentration is an independent correlate of muscle performance in older persons. Whether magnesium supplementation improves muscle function remains to be shown.
Another study in 2010 with adult range 51 to 85 years shown that low magnesium status and poor quality sleep was associated with a significantly higher body mass index (BMI) and inflammatory stress.
The two major classes of polyunsaturated fatty acids (PUFAs) are the omega-3 and omega-6 fatty acids. They’re important for your eyes, brain, and sperm cells. They also could help protect against age-related disease like Alzheimer’s, arthritis, and macular degeneration. 
you can get your omega-3s from food like fatty fish, walnuts, canola oil, or flaxseed, edamame. Salmon.
A 2013 study showed that daily supplementation with 1,000 mg omega-3s (650 mg EPA plus 350 mg DHA) for 3 months in 518 men and women (mean age about 40 years) living in northern India reduced symptoms and some signs of dry eye disease.
LC omega-3s are present in several dietary supplement formulations, including fish oil, krill oil, cod liver oil, and vegetarian products that contain algal oil. To find supplements with these ingredients you can refer to Dietary Supplement Label Database..
Zinc plays a key role in genetic expression, cell division, and growth and is essential for function of more than 200 enzymes. Zn deficiency include skin changes, poor appetite, mental lethargy, delayed wound healing, neurosensory disorders, and cell-mediated immune disorders.
According to experimental studies, zinc plays an important role in many age-related diseases, such as the aging of the main homeostatic mechanisms of the body, namely the nervous, neuroendocrine and immune systems.
Taking a supplement of antioxidants plus zinc may protect your vision.
You can get zinc from beef, crab, oysters and fortified breakfast cereals.
To know more about RDA for zinc you can refer to Recommended Dietary Allowances (RDAs) for Zinc.
Potassium plays a part in almost everything inside your body, including your heart, kidneys, muscles, and nerves. It also may help protect against stroke, high blood pressure, and osteoporosis. For people age 51 and over, 3400 mg for men and 2600mg for women per day is adequate. (Table 1: Adequate Intakes (AIs) for Potassium)
Good sources for Potassium: Many different fruits, vegetables, meats, and dairy foods contain potassium. Foods high in potassium include dried apricots, lentils, and potatoes. Adults get a lot of their potassium from milk, coffee, tea, and other nonalcoholic beverages.
Other vitamins and supplements
AREDS 2 nutritional supplement
Age-related macular degeneration (AMD) is one of the main causes of vision loss in older adults.
Researchers from the original 2001 Age-Related Eye Disease (AREDS) study reported that a nutritional supplement called the AREDS formulation may reduce the risk of developing advanced AMD.
AREDS ‘original formulation contained vitamin C, vitamin E, beta-carotene, zinc and copper and is sold today as Bausch and Lomb Preservision (AREDS).
In 2006, the same research group based at the NIH National Eye Institute started a second study called AREDS2 to determine if they could improve or modify the AREDS formulation.
According to The Age Related Eye Disease Study 2 (AREDS2) in 2012, supplementation with certain micronutrients reduces by 25 percent the progression of dry AMD into the more advanced stage in which vision loss occurs.
AREDS2 Formula Contains:
vitamin C 500mg , vitamin E 400IU, zinc oxide 80mg or 25mg, cupric oxide 2mg, lutein 10 milligrams (mg), zeaxanthin 2mg
A good balanced diet – filled with fruits and vegetables, low-fat dairy products, lots of fluids, healthier oils, good proteins, and whole grains is best for health. Sometimes it is difficult to know exactly what you need. If you’re still worried, ask your doctor if supplements can help.
7]Barbara J Boucher the Problems of Vitamin D Insufficiency in Older People. Published online 2012 Jun 6