Too much of a good thing can be bad for you
Vitamin and mineral supplements are good for you, especially if you’re unable to get the recommended amounts through food. But too much of a good thing can negate health benefits, possibly creating health risks, particularly where vitamins A and D and calcium are concerned.
Why you need it: Vitamin A is crucial to eye health. It’s also a key component for healthy skin and hair, and it boosts your immunity. If you need more in your diet, you might experience night blindness, dry skin around your eyes, coarse hair and respiratory infections.
How too much can hurt: Your body stores fat-soluble vitamins, like vitamin A, which can lead to toxicity. Two signs of vitamin A toxicity are headache and skin rashes. Research also suggests too much vitamin A may work against vitamin D, causing osteoporosis. Here’s what makes the problem worse: Vitamin A is present in many different supplements compounds. People taking a variety of supplements are getting much more than the recommended daily 5,000 international units (IU) of vitamin A.
The fix: Get your vitamin A from orange-colored vegetables and fruit—carrots, papayas, squash and sweet potatoes. Dark green, leafy vegetables and egg yolks are also good dietary sources of A.
Why you need it: Vitamin D partners with calcium to fortify your bones. Some research shows it also improves asthma and depression. And vitamin D strengthens your immune system. Your skin makes this vitamin after exposure to the sun’s ultraviolet rays. But because we are an indoor society we cover our skin with clothing and sunscreen when we head outside, making most Americans deficient in vitamin D. We have blood levels in the 20s, and many doctors recommend vitamin D supplements to bring blood levels up to 30 ng/mL. Past studies have suggested improved benefits when vitamin D levels are closer to 50 ng/mL.
How too much can hurt: Vitamin D blood levels higher than 100 ng/mL can be dangerous. The extra vitamin D triggers extra calcium absorption, which can cause muscle and abdominal pain, mood disorders and kidney stones. It may also raise the risk for heart attack and stroke. Most reports of toxicity involve patients taking synthetic vitamin D2.
The fix: A simple blood test can determine your levels of vitamin D. If you’re deficient, talk to your doctor about natural vitamin D3 supplements. See your doctor every three months until you reach steady vitamin D blood levels, about six to 12 months. After that, checkups every year or every other year are fine.
Why you need it: Calcium is critical for building and maintaining healthy bones. For decades, medical professionals have recommended high-dose calcium supplements to prevent osteoporosis, the bone-thinning disease responsible for fractures in elderly women and men.
How too much can hurt: Recent studies are showing increased risks for heart attack and stroke among people taking calcium 1,000 to 1,200 milligrams per day. Researchers believe without adequate vitamin D to help absorb the extra calcium, it settles in the arteries instead of the bones. There, it helps form plaques that threaten the heart and brain. Excess calcium can also cause muscle and tummy pain, mood disorders and kidney stones.
The fix: Your body absorbs calcium from food better than from calcium supplements. The best source of dietary calcium is fat-free organic Greek yogurt, which is loaded with calcium, plus vitamin D and protein. Just two servings fulfill your calcium needs for a full day. Other good sources of calcium include leafy green veggies, like spinach and kale; legumes and beans; sardines; salmon with soft bones; sesame seed; and fortified foods, like orange juice, milk, soy and almond milk.
The bottom line: You should get as many vitamins and nutrients as you can from your food. But changes in farming practices mean a lower nutrient content in many of our fruits and vegetables, so many people still need help meeting the recommended amounts. Have your nutrient levels assessed and, if necessary, take a high-quality daily multivitamin.