Vitamins are essential to almost every process in your body — from bone growth to vision—throughout your life.
But you may not know that for adults, the recommended intake of each vitamin varies by age and gender, and may need to be adjusted based on specific health issues. Not meeting those special nutritional needs can lead to deficiencies and/or a variety of health issues.
We asked Kristin Gustashaw, MS, RDN, CSG, LDN, an advanced clinical dietitian at Rush who has helped people maximize their nutritional health for more than 20 years, to explain some key times when people need to boost their vitamin intake.
1. Before conception, while pregnant and while breastfeeding
Work with a doctor and dietitian before, during and after pregnancy to ensure both mom and baby are getting the right mix of all nutrients, including vitamins, says Gustashaw.
Women need adequate folate at the time of conception to prevent neural tube defects — such as spina bifida — and even more folate while pregnant and breastfeeding to maintain and replenish their own store of folate. Good sources of folate include fortified cereals, citrus fruits, leafy green vegetables, peas and beans.
To fuel the body and help their babies grow, pregnant women actually need to consume more of most vitamins, including vitamin A, vitamin C, Thaimin (B1), Riboflavin (B2), Niacin (B3) Pyridoxine (B6), vitamin B12 and pantothenic acid. Taking a daily prenatal vitamin is a great way to bridge shortages in your diet.
After giving birth, women who breastfeed need all of the above vitamins, plus additional vitamin C, biotin, choline, riboflavin and vitamin E. It's easy to get most of these extra vitamins from food, coupled with the same prenatal multivitamin you take during pregnancy.
2. After age 50
At this time in your life, your body needs more vitamin D (ask your doctor how much is right for you). A deficiency of vitamin D, which aids in the absorption of calcium, may enhance the process of osteoporosis.
Dairy products are good and easily absorbed sources of both vitamin D and calcium. But as we age, many people lose their ability to digest the lactose (sugar) in milk. According to Gustashaw, 1 in 10 adults report having lactose intolerance, and many others simply stopped drinking milk after childhood.
Because there aren't many good food sources of vitamin D, and aging skin has less ability to process vitamin D from the sun, it may be necessary to take a vitamin D supplement to prevent deficiency.
When taking some vitamin supplements, use caution, because loading up vitamins can actually do more harm than good.
You may also need more B12 once you turn 50. Like the other B vitamins, B12 is essential for your metabolism; it helps in the formation of red blood cells and in the maintenance of the central nervous system. A B12 deficiency can result in irreversible memory loss, but fortunately, once B12 is replenished no further loss occurs.
If you're 50 or older, it's critical to have your B12 checked annually to make sure you're not deficient. Ask your physician to consider measuring your serum B12 to see if you need to take supplements or consume more B12-rich foods. Liver, beef, chicken, pork, ham, fish, whole eggs, milk, cheese and yogurt are all excellent sources of this crucial vitamin.
It's important to note that many people over the age of 50 lose the ability to extract B12 from ingested food and have to rely on vitamin supplementation to meet their needs. In fact, some individuals may be so inefficient at metabolizing B12 that they require a B12 shot every three months.
3. After age 70
After age 70, your body requires even more vitamin D. Though the majority of research is on vitamin D as it relates to bone health, vitamin D also plays a role in normal cell growth, strengthening your immune system, preventing or controlling diabetes, and regulating blood pressure.
The problem is that it's extremely difficult to get the amount of vitamin D your body needs at this stage of life. In fact, most people over the age of 70 require vitamin supplements, because they aren't able to get enough from food alone.
Your skin can make vitamin D from sunlight, but there are some caveats.
- In North America, only the far southern states provide enough year-round sunlight to provide the vitamin D you need.
- Aging skin and dark-complected skin produce less vitamin D from sunlight.
- Sunscreen, though essential to protect against sun damage, also affects how much sunlight your skin absorbs and, therefore, how much vitamin D it can generate.
"That’s why establishing regular adequate food and supplement sources is important," Gustashaw explains. "Although 5 to 10 daily minutes of sunlight without sunscreen will help you reach your goals, the vitamin D you get from the sun should be considered as a bonus and not your sole source of the vitamin."
Talk to your doctor about having your serum vitamin D checked annually once you celebrate your 70th birthday, to make sure your levels are OK.
Vitamin do's and don'ts
- Ideally, most vitamins should come from a healthy, varied and balanced diet. "A well-balanced diet is the best place to get your vitamins because of the natural synergy that exists when nutrients are metabolized from their natural form," Gustashaw says.
She encourages people to eat at least five servings of fruits and vegetables each day and "vary your fruits and veggies" to make sure you're consuming a broad range of vitamins.
To get the vitamins you need, follow the rainbow. "Nature has an amazing way of leading us to vitamin-rich fruits and vegetables by way of color." For example, a half-cup of red bell pepper is an excellent source of vitamins A, C and B6. Most people know that oranges are good sources of vitamin C, but they’re also rich in thiamin, folate and potassium. And two medium carrots have more vitamin A than most adults need in a day.
Another tip: Select fruits and vegetables based on what's in season. "This helps you naturally vary your selections," Gustashaw says. "Plus, fresh produce can lose nutrients fast, so eating fruits and veggies as close as possible to when they are harvested helps ensure a higher vitamin content — and, of course, produce tastes better when it’s fresh."
- Go easy on nutrient-poor foods. Too many adults fill their daily caloric needs with junk food and soft drinks, and meet or exceed their caloric needs quickly, Gustashaw says, but these foods are nutrient poor and leave the body deprived of essential building blocks on a regular basis.
If your diet is heavy in nutrient-poor foods, don't fret. Start by making small changes, like adding in one fruit or vegetable to each meal while gradually paring down your portions of the unhealthy choices.
- Alcohol significantly depletes vitamins in the body and should be consumed in moderation (one daily drink for women and two for men).
- When taking vitamin supplements, remember: More is not better. "There is a misconception that if something is good for us, more should be better," Gustashaw explains. "However, taking mega doses of some nutrients can result in severe complications."
For instance, consistently exceeding the recommended daily allowance of vitamin A — 900 micrograms daily for males age 14 and older; 700 micrograms daily for women age 14 and older — can lead to headaches, birth defects, liver damage, bone and joint pain, and other serious problems. And consuming mega doses of vitamin E may be associated with increased risk of hemorrhagic stroke and/or premature death.
When it comes to vitamins, there’s a lot of information to digest. So if you aren’t sure about whether you’re getting enough of certain nutrients or how to address a deficiency, talk to your doctor or a dietitian. They can help you find the right balance for optimal lifelong health.