Vitamin B6 for Depression
Even marginal deficiencies of the B vitamins have been associated with irritability, depression and mood changes. And if you’ve suffered from PMS, chances are you’ve already heard about vitamin B6 (chapter 17, “Premenstrual Syndrome (PMS)” has plenty on this subject). This B vitamin has been the focus of study in more than 900 women suffering from PMS.2 Based on the evidence available, a daily supplement of B6 seems likely to balance emotions in women suffering from PMS-related depression.
The body uses B6 to form an important enzyme that’s needed to convert tryptophan to serotonin, a brain chemical that has a calming and relaxing effect. Healthy women need 1.6 milligrams of the vitamin each day. The best sources of B6 are high-protein foods like meat, fish, and poultry. Other good sources include whole grains, bananas and potatoes. To see how common foods stack up for vitamin B6, see the B6 in Foods table on page 5 in chapter 1.
If you’re depressed and you’d like to see if a daily supplement could help, reach for a 50- to 100-milligram pill once a day. Because the eight B vitamins work together,
I recommend a B complex supplement that’s balanced with all the B’s. Taking only one B vitamin in high doses could upset the body’s balance. Don’t take more than 100 milligrams of B6 each day, since too much can cause irreversible nerve damage.
Folate and Vitamin B12
A number of studies have found that many depressed people are deficient in both of these B vitamins. It has been suggested that lack of these interrelated nutrients may work in a number of ways to cause depression. Both folate and B12 are required in the body for the synthesis of a compound called S-adenosylmethionine or SAMe (read more on this on page 223). SAMe, in turn, is used by the brain to produce neurotransmitters, in particular the amines. So a lack of B12 and/or folate can interfere with this process, resulting in low levels of brain amines that could cause or worsen depression.
A folate deficiency may also impair the brain’s ability to synthesize many neurotransmitters including serotonin, the calming chemical you read about earlier. If you are taking any of the serotonin reuptake inhibitor drugs (Prozac®, Effexor®, Paxil®, Zoloft®, Serzone®) for depression, you might be interested to learn that low folate levels in the body are linked with a poorer response to these antidepressant drugs.
While scientists are still unraveling the intricacies involved in B vitamins and mood disorders, it’s prudent to make sure your diet is giving you what you need.
1. Folate RDA is 400 micrograms (pregnancy 600 mcg; breastfeeding 500 mcg). Best food sources include spinach, artichokes, asparagus, lentils, dried peas and beans, chicken liver, orange juice and wheat germ (turn to page 7 in chapter 1 for a detailed food list). If you supplement, choose a multivitamin and mineral formula with 0.4 to 1 milligrams (400 to 1000 micrograms) of folic acid—the synthetic form of folate—or choose a B complex formula. If you take single supplements of folate, make sure it has B12 added. The daily upper limit for folate is 1000 micrograms.
2. Vitamin B12 RDA is 2.4 micrograms (pregnancy 2.6 mcg; breastfeeding 2.8 mcg). Best food sources include all animal foods and fortified soy and rice beverages (see page 9 in chapter 1 for a detailed food list). If you are over the age of 50, you should get your B12 from a supplement or fortified foods since we absorb less of this nutrient as we age. Supplement choices include a multivitamin and mineral or a B complex formula. If you are a complete vegetarian and you do not use fortified soy or rice beverages, take a single B12 supplement providing 500 to 1000 micrograms.