Test your B _IQ

When we are feeling fatigued or anxious, many of us take vitamin B complex. But B vitamins are more than a pick-me-up. They are critical to a host of metabolic processes, as you will discover in the B-vitamin quiz.

Food is definitely the best source of B vitamins, but vitamin-B supplements are better choices for the elderly and for those people with inadequate diets.

B complex is a natural combination of vitamins B₁, B₂, B₃, B₅ (pantothenic acid), B₆, folic acid, biotin, choline, inositol, and para-aminobenzoic acid (PABA). Experts recommend that we take a balanced B-complex vitamin every day, rather than supplement with individual B vitamins. Supplement with individual B vitamins only in an informed manner.

Take this B-vitamin Quiz

True or false? Answers are set out below.

Elderly people with low vitamin B₁ (thiamine) levels–a common condition–saw improvements in quality of life, including lower blood pressure and reduced weight, when supplementing with thiamine.

True. Results of a randomly assigned, double-blind study of 222 people age 65 years and older were reported in 1997 in the American Journal of Clinical Nutrition. Study participants took 10 mg of vitamin B₁ daily or placebo. After three months, those taking vitamin B₁ reported enhanced quality of life, lower blood pressure, and weight reduction.

Vitamin B₂ (riboflavin) may prevent migraines.

True. In 1998, Belgian researchers reported in the journal Neurology that they had compared 400 mg doses of riboflavin and placebo in 55 patients with migraines in a randomized trial of three months’ duration. Riboflavin was superior to placebo in reducing attack frequency and headache days.

Prescription drugs, including birth control pills, may deplete the body of B vitamins.

True. Oral contraceptive use has been linked to lower levels of vitamins B₁, B₂, and B₆, and folic acid, although the relationship is inconsistent and poorly understood. Supplementation beyond current recommended daily allowances is not generally considered necessary.

Studies over the past 20 years suggest that vitamin B₃ (niacin) may support healthy cholesterol levels.

True. A number of studies indicate that high doses of vitamin B₃ reduce triglyceride levels and increase high-density lipoprotein (HDL, or good cholesterol) levels. One well-controlled 16-week study involving 148 patients conducted at the University of Texas found that a 1,000 mg daily dose of niacin increased HDL by almost 20 percent. Although promising, high doses of niacin have the potential to promote liver damage and should not be used without medical supervision.

It is important to add choline to your swimming pool.

False. We add chlorine to a pool, and choline to our bodies. That’s because choline may be beneficial for those suffering from Parkinson’s disease. Participants who took 400 mg of choline three times daily during a four-week, single-blind study performed as well on a standardized test designed to evaluate the severity of Parkinson’s disease symptoms as participants who received their usual dose of dopamine medication.

Vitamin B₆ deficiency is linked to carpal tunnel syndrome.

True. In 1997 the Journal of Environmental and Occupational Medicine reported a cross-sectional study among 441 adult volunteers from six industries. Those with lower blood plasma concentrations of vitamin B₆ experienced more pain, tingling, and night waking due to carpal tunnel syndrome. Between 100 and 200 mg of vitamin B₆ per day is recommended to reduce symptoms of carpal tunnel syndrome; however, the US Institute of Medicine recently established an upper tolerable limit of 100 mg per day for adults.

Folic acid prevents several common birth defects.

True. It is widely accepted that supplementation with folic acid reduces the risk of neural tube defects, as well as cleft lip, heart defects, and abnormal limbs. In 1999 the American Journal of Epidemiology reported the results of a case-control study that tested this hypothesis and concluded that daily multivitamin supplementation that includes folic acid, before and during pregnancy, was wise prevention for birth defects. Health Canada recommends women of childbearing age take 0.4 mg daily.

Para-aminobenzoic acid (PABA) is used exclusively as a sunscreen.

False. Although PABA has been added to sunscreens, most people now look for PABA-free products as external application of PABA has been shown to cause contact dermatitis. Taken internally, PABA reverses greying hair in some circumstances.